Bulked continuous carpet filament manufacturing from polytrimethylene terephthalate

ABSTRACT

A method of manufacturing bulked continuous carpet filament from polytrimethylene terephthalate (PTT) with polyethylene terephthalate (PET) comprises: (1) splitting the PTT stream extruded from the primary extruder into a number of polymer streams, each of the plurality of polymer streams having an associated spinning machine; (2) adding a colorant to each split polymer stream; (3) adding PET to the extruded polymer stream downstream of the primary extruder; (4) using one or more static mixing assemblies for each split polymer stream to substantially uniformly mix each split polymer stream and its respective colorant and PET; and (5) spinning each polymer stream with its substantially uniformly mixed colorant and any additives into BCF using the respective spinning machine.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/701,388, filed Jul. 20, 2018, entitled “BULKED CONTINUOUS CARPETFILAMENT MANUFACTURING FROM POLYTRIMETHYLENE TEREPHTHALATE,” thecontents of which are hereby incorporated herein by reference in theirentirety.

BACKGROUND

Currently, bulked continuous carpet filament (BCF) is commonly made frompolymers such as polyethylene terephthalate (PET). There is currently aneed for improved methods for manufacturing BCF from other polymersand/or other combinations of polymers to provide BCF with improvedproperties (e.g., lower flammability) at a reasonable cost.

SUMMARY

According to particular embodiments, bulked continuous carpet filamentmay be manufactured from polytrimethylene terephthalate (PTT) byproviding an extruder, using the extruder to at least partially melt thePTT into a polymer stream and at least partially purify the polymerstream, providing a static mixing assembly downstream of the extruder,adding polyethylene terephthalate (PET) to the polymer stream downstreamof the extruder and before the static mixing assembly or along a lengthof the static mixing assembly between an upstream end and a downstreamend of the static mixing assembly, using the static mixing assembly tomix the polymer stream with the PET to create a mixed polymer stream,and forming the mixed polymer stream into bulked continuous carpetfilament. A liquid colorant may be added to the polymer stream beforethe static mixing assembly or along the length of the static mixingassembly between the upstream end and the downstream end of the staticmixing assembly. The static mixing assembly may mix the polymer streamwith the PET and the liquid colorant to create a colored mixed polymerstream. The colored mixed polymer stream may be formed into the bulkedcontinuous carpet filament. A molten polymeric masterbatch may be addedto the polymer stream before the static mixing assembly or along thelength of the static mixing assembly between the upstream end and thedownstream end of the static mixing assembly. The static mixing assemblymay mix the polymer stream with the PET and the molten polymericmasterbatch to create a colored mixed polymer stream. The colored mixedpolymer stream may be formed into the bulked continuous carpet filament.

An extruder used in manufacturing bulked continuous carpet filament maybe a multi-screw extruder, which may also be referred to as a multiplescrew extruder.

A polymer stream may be split into a plurality of individual polymerstreams downstream from the extruder (e.g., a multi-screw extruder) anda respective secondary extruder and a respective static mixing assemblymay be provided for each of the individual polymer streams. Adding PET,using a static mixing assembly, and forming a mixed polymer stream intobulked continuous carpet filament may occur with respect to each streamof the plurality of individual polymer streams. A liquid colorant may beadded to each stream of the plurality of individual polymer streamsbefore the respective static mixing assembly or along the length of therespective static mixing assembly between the upstream end and thedownstream end of the static mixing assembly. Each respective staticmixing assembly may mix each stream of the plurality of individualpolymer streams with the PET and the liquid colorant to create arespective colored mixed polymer stream and the respective colored mixedpolymer stream may be formed into the bulked continuous carpet filament.A molten polymeric masterbatch may be added to each stream of theplurality of individual polymer streams. Each respective static mixingassembly may mix each stream of the plurality of individual polymerstreams with the PET and the molten polymeric masterbatch to create arespective colored mixed polymer stream and the respective colored mixedpolymer stream into the bulked continuous carpet filament. Moltenpolymeric masterbatch may be added to each stream of the plurality ofindividual polymer streams by adding the molten polymeric masterbatch tothe respective secondary extruder. Molten polymeric masterbatch may beadded to each stream of the plurality of individual polymer streams byadding the molten polymeric masterbatch before the respective staticmixing assembly or along the length of the respective static mixingassembly between the upstream end and the downstream end of therespective static mixing assembly.

In multi-screw extruder embodiments, adding PET, using a static mixingassembly, and forming a mixed polymer stream into bulked continuouscarpet filament may occur with respect to each stream of the pluralityof individual polymer streams. In multi-screw extruder embodiments, aliquid colorant may be added to each stream of the plurality ofindividual polymer streams before the respective static mixing assemblyor along the length of the respective static mixing assembly between theupstream end and the downstream end of the static mixing assembly. Eachrespective static mixing assembly may mix each stream of the pluralityof individual polymer streams with the PET and the liquid colorant tocreate a respective colored mixed polymer stream and the respectivecolored mixed polymer stream may be formed into the bulked continuouscarpet filament. In further multi-screw extruder embodiments, a moltenpolymeric masterbatch may be added to each stream of the plurality ofindividual polymer streams. Each respective static mixing assembly maymix each stream of the plurality of individual polymer streams with thePET and the molten polymeric masterbatch to create a respective coloredmixed polymer stream and the respective colored mixed polymer streaminto the bulked continuous carpet filament. In multi-screw extruderembodiments, molten polymeric masterbatch may be added to each stream ofthe plurality of individual polymer streams by adding the moltenpolymeric masterbatch to the respective secondary extruder. In othermulti-screw extruder embodiments, molten polymeric masterbatch may beadded to each stream of the plurality of individual polymer streams byadding the molten polymeric masterbatch before the respective staticmixing assembly or along the length of the respective static mixingassembly between the upstream end and the downstream end of therespective static mixing assembly.

According to further embodiments, bulked continuous carpet filament maybe manufactured from PTT by providing an extruder, using the extruder toat least partially melt the PTT into a polymer stream and at leastpartially purify the polymer stream, providing a static mixing assemblydownstream of the extruder, adding a liquid colorant to the polymerstream before the static mixing assembly or along a length of the staticmixing assembly between an upstream end and a downstream end of thestatic mixing assembly, using the static mixing assembly to mix thepolymer stream with the liquid colorant to create a colored polymerstream, and forming the colored polymer stream into bulked continuouscarpet filament. PET may be added to the polymer stream and the staticmixing assembly may mix the polymer stream with the liquid colorant andthe PET to create a colored mixed polymer stream that may be formed intothe bulked continuous carpet filament. PET may be to the polymer streamby adding the PET to the extruder. PET may be added to the polymerstream by adding the PET before the static mixing assembly or along thelength of the static mixing assembly between the upstream end and thedownstream end of the static mixing assembly.

A polymer stream may be split into a plurality of individual polymerstreams downstream from the extruder (e.g., multi-screw extruder). Arespective secondary extruder and a respective static mixing assemblymay be provided for each stream of the plurality of individual polymerstreams, wherein adding the liquid colorant, using the static mixingassembly, and forming the colored polymer stream into the bulkedcontinuous carpet filament may occur with respect to each stream of theplurality of individual polymer streams. PET may be added to each streamof the plurality of individual polymer streams and a respective staticmixing assembly may mix each of the plurality of individual polymerstreams with the liquid colorant and the PET to create a respectivecolored mixed polymer stream that may be formed into bulked continuouscarpet filament. The PET may be added to each of the plurality ofindividual polymer streams by adding the PET before the respectivestatic mixing assembly or along the length of the respective staticmixing assembly between the upstream end and the downstream end of therespective static mixing assembly.

In multi-screw extruder embodiments, PET may be added to each stream ofthe plurality of individual polymer streams and a respective staticmixing assembly may mix each of the plurality of individual polymerstreams with the liquid colorant and the PET to create a respectivecolored mixed polymer stream that may be formed into bulked continuouscarpet filament. The PET may be added to each of the plurality ofindividual polymer streams by adding the PET before the respectivestatic mixing assembly or along the length of the respective staticmixing assembly between the upstream end and the downstream end of therespective static mixing assembly.

According to further embodiments, bulked continuous carpet filament maybe manufactured from PTT by providing an extruder, using the extruder toat least partially melt the PTT into a polymer stream and at leastpartially purify the polymer stream, providing a static mixing assemblydownstream of the extruder, adding a molten polymeric masterbatch to thepolymer stream before the static mixing assembly or along a length ofthe static mixing assembly between an upstream end and a downstream endof the static mixing assembly, using the static mixing assembly to mixthe polymer stream with the molten polymeric masterbatch to create acolored polymer stream, and forming the colored polymer stream intobulked continuous carpet filament. PET may be added to the polymerstream and the static mixing assembly may mix the polymer stream withthe molten polymeric masterbatch and the PET to create a colored mixedpolymer stream that may be formed into the bulked continuous carpetfilament.

A polymer stream may be split into a plurality of individual polymerstreams downstream from the extruder (e.g., multi-screw extruder). Arespective secondary extruder and a respective static mixing assemblymay be provided for each stream plurality of individual polymer streams,where adding the molten polymeric masterbatch, using the static mixingassembly, and forming the colored polymer stream into the bulkedcontinuous carpet filament may occur with respect to each stream of theplurality of individual polymer streams. PET may be added to each streamof the plurality of individual polymer streams and the respective staticmixing assembly may mix each stream of the plurality of individualpolymer streams with the molten polymeric masterbatch and the PET tocreate a respective colored mixed polymer stream that may be formed intobulked continuous carpet filament. The PET may be added to each streamof the plurality of individual polymer streams by adding the PET to therespective secondary extruder. The PET may be added to each of theplurality of individual polymer streams by adding the PET before therespective static mixing assembly or along the length of the respectivestatic mixing assembly between the upstream end and the downstream endof the respective static mixing assembly.

In multi-screw extruder embodiments, PET may be added to each stream ofthe plurality of individual polymer streams and the respective staticmixing assembly may mix each stream of the plurality of individualpolymer streams with the molten polymeric masterbatch and the PET tocreate a respective colored mixed polymer stream that may be formed intobulked continuous carpet filament. The PET may be added to each streamof the plurality of individual polymer streams by adding the PET to therespective secondary extruder. The PET may be added to each of theplurality of individual polymer streams by adding the PET before therespective static mixing assembly or along the length of the respectivestatic mixing assembly between the upstream end and the downstream endof the respective static mixing assembly.

Various embodiments are also described in the following listing ofconcepts:

1. A method of manufacturing bulked continuous carpet filament frompolytrimethylene terephthalate (PTT), the method comprising:

providing an extruder;

using the extruder to at least partially melt the PTT into a polymerstream and at least partially purify the polymer stream;

providing a static mixing assembly downstream of the extruder;

adding polyethylene terephthalate (PET) to the polymer stream downstreamof the extruder and before the static mixing assembly or along a lengthof the static mixing assembly between an upstream end and a downstreamend of the static mixing assembly;

using the static mixing assembly to mix the polymer stream with the PETto create a mixed polymer stream; and

forming the mixed polymer stream into bulked continuous carpet filament.

2. The method of concept 1, further comprising adding a liquid colorantto the polymer stream before the static mixing assembly or along thelength of the static mixing assembly between the upstream end and thedownstream end of the static mixing assembly,

wherein using the static mixing assembly to mix the polymer stream withthe PET to create the mixed polymer stream comprises using the staticmixing assembly to mix the polymer stream with the PET and the liquidcolorant to create a colored mixed polymer stream, and

wherein forming the mixed polymer stream into the bulked continuouscarpet filament comprises forming the colored mixed polymer stream intothe bulked continuous carpet filament.

3. The method of concept 1, further comprising adding a molten polymericmasterbatch to the polymer stream before the static mixing assembly oralong the length of the static mixing assembly between the upstream endand the downstream end of the static mixing assembly,

wherein using the static mixing assembly to mix the polymer stream withthe PET to create the mixed polymer stream comprises using the staticmixing assembly to mix the polymer stream with the PET and the moltenpolymeric masterbatch to create a colored mixed polymer stream, and

wherein forming the mixed polymer stream into the bulked continuouscarpet filament comprises forming the colored mixed polymer stream intothe bulked continuous carpet filament.

4. The method of concept 1, wherein the extruder optionally comprises amulti-screw extruder, the method further comprising:

splitting the polymer stream into a plurality of individual polymerstreams downstream from the extruder; and

providing, for each stream of the plurality of individual polymerstreams, a respective secondary extruder and a respective static mixingassembly, wherein adding the PET, using the static mixing assembly, andforming the mixed polymer stream into bulked continuous carpet filamentoccurs with respect to each stream of the plurality of individualpolymer streams.

5. The method of concept 4, further comprising adding a liquid colorantto each stream of the plurality of individual polymer streams before therespective static mixing assembly or along the length of the respectivestatic mixing assembly between the upstream end and the downstream endof the static mixing assembly,

wherein using the static mixing assembly to mix the polymer stream withthe PET to create the mixed polymer stream comprises using therespective static mixing assembly to mix each stream of the plurality ofindividual polymer streams with the PET and the liquid colorant tocreate a respective colored mixed polymer stream, and

wherein forming the mixed polymer stream into the bulked continuouscarpet filament comprises forming the respective colored mixed polymerstream into the bulked continuous carpet filament.

6. The method of concept 4, further comprising adding a molten polymericmasterbatch to each stream of the plurality of individual polymerstreams,

wherein using the static mixing assembly to mix the polymer stream withthe PET to create the mixed polymer stream comprises using therespective static mixing assembly to mix each stream of the plurality ofindividual polymer streams with the PET and the molten polymericmasterbatch to create a respective colored mixed polymer stream, and

wherein forming the mixed polymer stream into the bulked continuouscarpet filament comprises forming the respective colored mixed polymerstream into the bulked continuous carpet filament.

7. The method of concept 6, wherein adding the molten polymericmasterbatch to each stream of the plurality of individual polymerstreams comprises adding the molten polymeric masterbatch to therespective secondary extruder.

8. The method of concept 6, wherein adding the molten polymericmasterbatch to each stream of the plurality of individual polymerstreams comprises adding the molten polymeric masterbatch before therespective static mixing assembly or along the length of the respectivestatic mixing assembly between the upstream end and the downstream endof the respective static mixing assembly.

9. A method of manufacturing bulked continuous carpet filament frompolytrimethylene terephthalate (PTT), the method comprising:

providing an extruder;

using the extruder to at least partially melt the PTT into a polymerstream and at least partially purify the polymer stream;

providing a static mixing assembly downstream of the extruder;

adding a liquid colorant to the polymer stream before the static mixingassembly or along a length of the static mixing assembly between anupstream end and a downstream end of the static mixing assembly;

using the static mixing assembly to mix the polymer stream with theliquid colorant to create a colored polymer stream; and

forming the colored polymer stream into bulked continuous carpetfilament.

10. The method of concept 9, further comprising adding polyethyleneterephthalate (PET) to the polymer stream;

wherein using the static mixing assembly to mix the polymer stream withthe liquid colorant to create the colored polymer stream comprises usingthe static mixing assembly to mix the polymer stream with the liquidcolorant and the PET to create a colored mixed polymer stream, and

wherein forming the colored polymer stream into the bulked continuouscarpet filament comprises forming the colored mixed polymer stream intothe bulked continuous carpet filament.

11. The method of concept 10, wherein adding the PET to the polymerstream comprises adding the PET to the extruder.

12. The method of concept 10, wherein adding the PET to the polymerstream comprises adding the PET before the static mixing assembly oralong the length of the static mixing assembly between the upstream endand the downstream end of the static mixing assembly.

13. The method of concept 9, wherein the extruder optionally comprises amulti-screw extruder, the method further comprising:

splitting the polymer stream into a plurality of individual polymerstreams downstream from the extruder; and

providing, for each stream of the plurality of individual polymerstreams, a respective secondary extruder and a respective static mixingassembly, wherein adding the liquid colorant, using the static mixingassembly, and forming the colored polymer stream into the bulkedcontinuous carpet filament occurs with respect to each stream of theplurality of individual polymer streams.

14. The method of concept 13, further comprising adding polyethyleneterephthalate (PET) to each stream of the plurality of individualpolymer streams,

wherein using the static mixing assembly to mix the polymer stream withthe liquid colorant to create the colored polymer stream comprises usingthe respective static mixing assembly to mix each stream of theplurality of individual polymer streams with the liquid colorant and thePET to create a respective colored mixed polymer stream, and

wherein forming the colored polymer stream into the bulked continuouscarpet filament comprises forming the respective colored mixed polymerstream into the bulked continuous carpet filament.

15. The method of concept 14, wherein adding the PET to each stream ofthe plurality of individual polymer streams comprises adding the PETbefore the respective static mixing assembly or along the length of therespective static mixing assembly between the upstream end and thedownstream end of the respective static mixing assembly.

16. A method of manufacturing bulked continuous carpet filament frompolytrimethylene terephthalate (PTT), the method comprising:

providing an extruder;

using the extruder to at least partially melt the PTT into a polymerstream and at least partially purify the polymer stream;

providing a static mixing assembly downstream of the extruder;

adding a molten polymeric masterbatch to the polymer stream before thestatic mixing assembly or along a length of the static mixing assemblybetween an upstream end and a downstream end of the static mixingassembly;

using the static mixing assembly to mix the polymer stream with themolten polymeric masterbatch to create a colored polymer stream; and

forming the colored polymer stream into bulked continuous carpetfilament.

17. The method of concept 16, further comprising adding polyethyleneterephthalate (PET) to the polymer stream,

wherein using the static mixing assembly to mix the polymer stream withthe molten polymeric masterbatch to create the colored polymer streamcomprises using the static mixing assembly to mix the polymer streamwith the molten polymeric masterbatch and the PET to create a coloredmixed polymer stream, and

wherein forming the colored polymer stream into the bulked continuouscarpet filament comprises forming the colored mixed polymer stream intothe bulked continuous carpet filament.

18. The method of concept 16, wherein the extruder optionally comprisesa multi-screw extruder, the method further comprising:

splitting the polymer stream into a plurality of individual polymerstreams downstream from the extruder; and

providing, for each stream of the plurality of individual polymerstreams, a respective secondary extruder and a respective static mixingassembly, wherein adding the molten polymeric masterbatch, using thestatic mixing assembly, and forming the colored polymer stream into thebulked continuous carpet filament occurs with respect to each stream ofthe plurality of individual polymer streams.

19. The method of concept 18, further comprising adding polyethyleneterephthalate (PET) to each stream of the plurality of individualpolymer streams,

wherein using the static mixing assembly to mix the polymer stream withthe molten polymeric masterbatch to create the colored polymer streamcomprises using the respective static mixing assembly to mix each streamof the plurality of individual polymer streams with the molten polymericmasterbatch and the PET to create a respective colored mixed polymerstream, and

wherein forming the colored polymer stream into the bulked continuouscarpet filament comprises forming the respective colored mixed polymerstream into the bulked continuous carpet filament.

20. The method of concept 19, wherein adding the PET to each stream ofthe plurality of individual polymer streams comprises adding the PET tothe respective secondary extruder.

Using a static mixing assembly according to all aspects, concepts, andembodiments disclosed herein is preferably used to substantiallythoroughly mix the components passing through the static mixingassembly. As used herein, “substantially thoroughly mixing” should beunderstood to refer to mixing that results in a mixture that, uponexiting the static mixing assembly, has an identical compositionthroughout. That is, when samples of the resulting mixture are taken atdifferent positions relative to the downstream end of the static mixingassembly, each sample should have an identical, or substantiallyidentical, composition.

BRIEF DESCRIPTION OF THE DRAWINGS

Having described various embodiments in general terms, reference willnow be made to the accompanying drawings, which are not necessarilydrawn to scale, and wherein:

FIG. 1 depicts a high-level overview of a manufacturing process forproducing and coloring bulked continuous filament, according to variousembodiments described herein;

FIG. 2 depicts a process flow, according to a particular embodiment, foradding a colorant and PET to a stream of molten polymer downstream froma first extruder, according to various embodiments described herein;

FIG. 3 is a perspective view of a multiple screw extruder that issuitable for use as the first extruder of FIG. 2, according to variousembodiments described herein;

FIG. 4 is a cross-sectional view of an exemplary multiple screw sectionof the multiple screw extruder of FIG. 2, according to variousembodiments described herein;

FIG. 5 is a cross-sectional end view of dispersion of a colorant in astream of molten polymer prior to passing through the one or more staticmixing assemblies shown in FIG. 2, according to various embodimentsdescribed herein;

FIG. 6 is a cross-sectional end view of dispersion of a colorant in astream of molten polymer following passing through the one or morestatic mixing assemblies shown in FIG. 2, according to variousembodiments described herein;

FIG. 7 is a cross-sectional end view of the exemplary one of the one ormore static mixing elements of FIG. 2, according to a particularembodiment, according to various embodiments described herein;

FIG. 8 is a side view of eight of the exemplary static mixing elementsof FIG. 7 coupled to one another to form a static mixing assembly,according to various embodiments described herein;

FIG. 9 is a perspective view of an exemplary helical static mixingassembly, according to various embodiments described herein;

FIG. 10 is a perspective cutaway view of the helical static mixingassembly of FIG. 9 showing four helical static mixing elements,according to various embodiments described herein;

FIG. 11 depicts a process flow, according to a particular embodiment,for adding various colorants and PET to several streams of moltenpolymer downstream from a first extruder, according to variousembodiments described herein;

FIG. 12 depicts a process flow, according to another embodiment, foradding various colorants and PET to several streams of molten polymerdownstream from a first extruder, according to various embodimentsdescribed herein;

FIG. 13 depicts a side view of a static mixing assembly havingindividual static mixing elements coupled to one another to form astatic mixing assembly and one or more color injection assembliescoupled to the static mixing assembly, according to various embodimentsdescribed herein;

FIG. 14 depicts a high-level overview of a manufacturing process forproducing and coloring a bulked continuous filament with a tonal coloreffect, according to various embodiments described herein;

FIG. 15 depicts a cross-sectional view of a polymer stream conduit witha color injection port and a polymer injection port for providing liquidcolorant and PET, respectively, to a polymer stream, according tovarious embodiments described herein;

FIG. 16A depicts a side view of a color injection port in a closedconfiguration with the color probe in a retracted position, according tovarious embodiments described herein;

FIG. 16B depicts a side view of a color injection port in an openconfiguration with the color probe in a deployed position, according tovarious embodiments described herein;

FIG. 16C depicts a cross-sectional view of a stream engaging portion ofa color injection port, illustrating leading and trailing edge flowcontrol devices, according to various embodiments described herein;

FIGS. 17A-17B depict front, side, and top views, respectively, of a PETinjection port, according to various embodiments described herein; and

FIG. 18 depicts a high-level overview of a process for introducing aliquid colorant into a polymer stream during manufacturing of a bulkedcontinuous filament, according to various embodiments described herein.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

Various embodiments will now be described in greater detail. It shouldbe understood that the disclosure herein may be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth below. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the disclosure to those skilled in the art. Likenumbers refer to like elements throughout.

Overview

New processes for producing and coloring fiber from recycled polymer(e.g., recycled PET polymer), virgin polymer (e.g., virgin PET polymer),and combinations of PTT and PET polymer are described below. In variousembodiments, these new processes may include, for example: (1) extrudinga polymer (e.g., such as PET or PTT) using a primary extruder; (2)adding a liquid colorant to the extruded polymer downstream from theprimary extruder and/or adding molten polymeric masterbatch to theextruded polymer downstream from the primary extruder; (3) changing acolor probe within a color injection port while maintaining the flow ofthe extruded polymer stream at the polymer stream pressure; (4) addingother polymers (e.g., such as PET) to the extruded polymer stream if theextruded polymer stream is substantially PTT; (5) using one or morestatic mixing elements (e.g., up to 36 static mixing elements or more)to substantially uniformly mix the extruded polymer, any added liquidcolorant, any added polymeric masterbatch, and any added PET; and (6)using a spinning machine to spin the uniformly mixed extruded polymerand added colorant/PTT into bulked continuous filament (BCF) that has acolor that is based on the added colorant and/or masterbatch. Theprocess described herein may, for example, reduce an amount of wasterelated to changing a color of BCF produced using a particular extruderwhen switching to a different coloring agent (e.g., a colorant forgenerating a different color or a polymeric masterbatch for generating adifferent color). Note that as used herein, the term “colorant” refers,for example, to any colorant, coloring agent, or coloring additive, inany form (e.g., solid, liquid, molten, etc.), for altering the color ofa polymer, including, but not limited to, liquid colorant, fullycompounded colorant, raw colorant material, and polymeric masterbatch.

In various embodiments, the primary extruder comprises a multi-rotatingscrew extruder (MRS extruder). In particular embodiments, the processmay further include, for example, one or more of: (1) splitting themolten polymer stream extruded from the primary extruder into aplurality of polymer streams (e.g., up to six polymer streams), each ofthe plurality of polymer streams having an associated spinning machine;(2) adding a colorant to each split polymer stream and/or adding moltenpolymeric masterbatch to each split polymer stream; (3) adding otherpolymers (e.g., such as PET) to each split polymer stream if therespective polymer stream is substantially PTT; (4) using one or morestatic mixing assemblies for each split polymer stream to substantiallyuniformly mix each split polymer stream and its respective colorant andother additives; and (5) spinning each polymer stream with itssubstantially uniformly mixed colorant and any additives into BCF usingthe respective spinning machine. In such embodiments, a process forproducing and coloring bulked continuous filament may utilize a singleprimary extruder to produce a plurality of different colored filaments(e.g., carpet yarn).

In various embodiments, this new process may, for example: (1) produceless waste than other processes when producing or changing a color ofBCF produced using a particular extruder, saving time, money, andproduct; (2) facilitate the production of small batches of particularcolors of filament (e.g., for use in rugs or less popular colors ofcarpet) at a relatively low cost; (3) increase a number of simultaneousfilament colors that a single extruder can produce; (4) allow forflexibility in manufacturing equipment and production lineconfigurations while maintaining a satisfactory mix time for a PET andPTT mixture prior to spinning; and (5) otherwise streamline themanufacture of PET and PTT carpet filament, while providing for multiplecolorant capabilities.

The various embodiments below will be described in both the context ofutilizing virgin or recycled PET polymer to create BCF and in thecontext of utilizing PTT to create BCF. When virgin or recycled PET isused to create BCF, additional polymers may not be added, while colorantand/or polymeric masterbatch may be added. Alternatively, when makingBCF using PTT, other polymers may be added to improve flammability andother characteristics of the resulting BCF. In embodiments where otherpolymers are added to PTT, colorant and/or polymeric masterbatch mayalso be added. Various embodiments herein will be described in thecontext of adding PET to a PTT stream. When PET or other polymers areadded to a stream of PTT and the mixture undergoes extrusion and mixingfor an extended time period, a chemical process calledtransesterification may occur. Transesterification results in a mixturethat is difficult to spin in the spinning machines.

Traditionally, transesterification is a factor because the time betweenadding PET to the PTT stream and spinning the resulting polymer streaminto BCF (this time period will be referred to herein as the “hold uptime”) is such that the transesterification may occur. However, whenutilizing production lines that employ a primary extruder on a primaryline before splitting the primary line into a number of secondary lines,each with secondary extruders and static mixing assemblies, as describedin the various embodiments below, transesterification may impede thespinning process. Accordingly, rather than adding PET or other polymersto the PTT stream at the primary extruder, as is traditionally done,embodiments described below provide for the addition of PET or otherpolymers to the PTT stream downstream of the primary extruder. The PETaddition may occur at the secondary extruders, at the static mixingassemblies, or within the static mixing assemblies (e.g., or in one ormore dynamic mixing assemblies). Adding PET or other polymers to the PTTstream downstream of the primary extruder can significantly shorten theholdup time, which may improve the characteristics of the mixed polymerstream prior to spinning the polymer mixture into BCF.

According to other aspects of the disclosure below, systems and methodsprovide for improved colorant additions to polymer streams and colorinjection ports that allow for the removal and replacement of colorprobes and/or color probe channel plugs without requiring a shutdown ofthe production line. Embodiments herein provide for liquid colorantinjections into a centered position (or other position) of the polymerstream while maintaining laminar flow characteristics of the polymerstream. Embodiments herein also provide for polymeric masterbatchinjections into a centered position of the polymer stream whilemaintaining laminar flow characteristics of the polymer stream. Colorinjection ports and assemblies accurately place the color probe withinthe polymer stream while providing for retraction and insertion of thecolor probe while maintaining the polymer stream at the desired polymerstream pressure. The color injection ports and assemblies prevent abackflow of the polymer stream through the color injection port when thecolor probe is removed and replaced (e.g., by another color probe or bya plug). In this manner, the production line may continue to run duringcolor probe replacement and color probe channel plugging, saving thesignificant amount of time and corresponding costs associated withstopping and starting the production line that is required inconventional color probe replacements.

More Detailed Discussion

FIG. 1 depicts a high-level overview of BCF manufacturing process 100for producing and coloring BCF, for example, for use in the productionof carpet and other products. The BCF manufacturing process, accordingto various embodiments, may generally be broken down into fiveoperations: (1) passing polymer flakes (e.g., PET or PTT) through anextruder that melts the flakes and purifies the resulting polymer(operation 102) to create a polymer stream; (2) optionally splitting theextruded polymer stream into a plurality of polymer streams and adding acolorant (e.g., a liquid colorant or molten polymeric masterbatch) toeach of the plurality of polymer streams (operation 104); (3) adding PETdownstream of the primary extruder if the polymer stream is PTT(operation 106) (if the polymer stream is PET, according to oneembodiment, no further PET or other polymers may be added); (4) usingone or more static mixing assemblies to substantially uniformly mix eachof the plurality of polymer streams with its respective added colorantand PET, if applicable (operation 108); and (5) feeding each of thesubstantially uniformly mixed and colored plurality of polymer streamsinto a respective spinning machine that turns the polymer into filamentfor use in manufacturing carpets (operation 110). These five operationsare described in greater detail below.

Operation 1: Using an Extrusion System to Melt and Purify PET or PTT

In various embodiments, the operation of using an extrusion system tomelt and purify PET (e.g., PET flakes and/or pellets) or PTT may includepreparing the PET or PTT for extrusion and using a suitable extruder tomelt and purify the PET or PTT. As discussed above, the embodimentsherein apply to both the processing of PET into BCF and the processingof PTT into BCF, as well as the processing of a mixed polymer (e.g., apolymer mixture that includes both PTT and PET) into BCF. It should beunderstood that the embodiments described with respect to thepreparation and processing of PET and with respect to the preparationand processing of PTT are interchangeable, with minor exceptions. Inother words, if a process is described with respect to processing a PETstream into a colored BCF product, it should be appreciated that thesame process applies to a PTT stream, unless described otherwise.

Such exceptions may include the processing of recycled PET preparationand the addition of PET to a PTT stream. The discussion of preparingrecycled consumer materials into PET flakes to create a PET stream doesnot apply to PTT since PTT does not originate from recycled consumermaterials. Moreover, when discussing the processing of a PTT stream intoa colored BCF product, PET may be added as described herein in order toimprove the flammability and other characteristics of the resultingproduct. The addition of PET may not be applicable to the processing ofa PET stream as there would be little benefit to doing so.

A. Preparing PET or PTT for Extrusion

In particular embodiments, the operation of preparing the PET forextrusion may vary based on a source of the PET. For example, in variousembodiments, the process may utilize: (1) virgin PET (e.g., in the formof virgin PET pellets); (2) recycled PET (e.g., in the form of recycledPET flakes ground from recycled PET bottles and other suitable sources);and/or (3) a combination of virgin and recycled PET. In variousembodiments utilizing recycled PET, the operation of preparing such PETfor extrusion may include sorting, grinding, washing, and/or otheroperations designed to remove any (e.g., some) impurities from therecycled PET prior to extrusion. These other PET preparation operationsmay, for example, be unnecessary in embodiments of the process thatutilize virgin PET or that utilize PTT. Because using recycled PET inthe process described herein may result in additional costs savingsbeyond those associated with a reduction in waste due to colorantchanging as described herein, the processes described herein mayparticularly focus on the use of recycled PET, but should not beunderstood to limit the disclosed embodiments to recycled PET only.

In a particular embodiment, preparing the PET for extrusion may includepreparing flakes of PET polymer from post-consumer bottles or othersources of recycled PET. An exemplary process for preparingpost-consumer bottles for use in the production of bulked continuousfilament is described in U.S. Pat. No. 8,597,553, entitled “Systems andMethods for Manufacturing Bulked Continuous Filament,” which is herebyincorporated herein in its entirety. The operation of preparing flakesof PET polymer from post-consumer bottles may include, for example: (A)sorting post-consumer PET bottles and grinding the bottles into flakes;(B) washing the flakes; and (C) identifying and removing any impuritiesor impure flakes.

Sorting Post-Consumer PET bottles and Grinding the Bottles into Flakes

In various embodiments, bales of clear and mixed colored recycledpost-consumer (e.g., “curbside”) PET bottles (or other containers)obtained from various recycling facilities may be used as a source ofpost-consumer PET containers for use in the disclosed systems andprocesses. In other embodiments, the source of the post-consumer PETcontainers may be returned “deposit” bottles (e.g., PET bottles whoseprice includes a deposit that is returned to a customer when thecustomer returns the bottle after consuming the bottle's contents). Thecurbside or returned “post-consumer” or “recycled” containers maycontain a small level of non-PET contaminates. The contaminants in thecontainers may include, for example, non-PET polymeric contaminants(e.g., polyvinyl chloride (PVC), polylactide (PLA), polypropylene (PP),polyethylene (PE), polystyrene (PS), polyamide (PA), etc.), metal (e.g.,ferrous metal, non-ferrous metal), paper, cardboard, sand, glass orother unwanted materials that may find their way into the collection ofrecycled PET. The non-PET contaminants may be removed from the desiredPET components, for example, through one or more of the variousprocesses described below.

In particular embodiments, smaller components and debris (e.g.,components and debris greater than 2 inches in size) are removed fromthe bottles or containers via a rotating trammel. Various metal removalmagnets and eddy current systems may be incorporated into the process toremove any metal contaminants.

In particular embodiments, the sorted material may be taken through agranulation operation (e.g., using a 50B Granulator machine fromCumberland Engineering Corporation of New Berlin, Wis.) to render,grind, shred, and/or otherwise size reduce the bottles or containersdown to a size, for example, of less than one half of an inch. NearInfra-Red optical sorting equipment such as a NRT Multi Sort IR machinefrom Bulk Handling Systems Company of Eugene, Oreg., or the Spyder IRmachine from National Recovery Technologies of Nashville, Tenn., may beutilized to remove any loose polymeric contaminants that may be mixed inwith the resultant “dirty flake” (e.g., the PET flakes formed during thegranulation operation) (e.g., PVC, PLA, PP, PE, PS, and PA).Additionally, or instead, automated X-ray sorting equipment such as aVINYLCYCLE machine from National Recovery Technologies of Nashville,Tenn. may be utilized to remove contaminants from the resultant dirtyflake. Additionally, or instead, automated color sorting equipmentequipped with a camera detection system such as a Multisort ES machinefrom National Recovery Technologies of Nashville, Tenn. may be utilizedto remove contaminants from the resultant dirty flake. Additionally, orinstead, any labels or other remaining waste may be removed from theresultant dirty flake via an air separation system prior to entering thewash process.

Washing the Flakes

In various embodiments, dirty flake may then be mixed into a series ofwash tanks. As part of the wash process, in various embodiments, anaqueous density separation may be utilized to separate bottle caps(e.g., olefin bottle caps) which may, for example, be present in thedirty flake as remnants from recycled PET bottles from the higherspecific gravity PET flakes. In particular embodiments, the flakes arewashed in a heated caustic bath to about 190 degrees Fahrenheit. Inparticular embodiments, the caustic bath is maintained at aconcentration of between about 0.6% and about 1.2% sodium hydroxide. Invarious embodiments, soap surfactants as well as defoaming agents areadded to the caustic bath, for example, to further increase theseparation and cleaning of the flakes. A double rinse system then washesthe caustic from the flakes.

In various embodiments, the washed PET polymer flakes may be dried as aninitial step in reducing the water content of the flakes. The flake maybe centrifugally dewatered and then dried with hot air to at leastsubstantially remove any surface moisture. To further dry the flakes,the system may place the flakes into a pre-conditioner for between about20 and about 40 minutes (e.g., about 30 minutes) during which apre-conditioner may blow the surface water off of the flakes.

The resultant “clean flake” may then be processed through anelectrostatic separation system (e.g., an electrostatic separator fromCarpco, Inc. of Jacksonville, Fla.) and/or a flake metal detectionsystem (e.g., an MSS Metal Sorting System) to further remove any metalcontaminants that remain in the flake. In particular embodiments, an airseparation operation may remove any remaining label fragments that maybe remaining from the clean flake. In various embodiments, the flake maybe color sorted using a flake color sorting step (e.g., using an OPTIMIXmachine from TSM Control Systems of Dundalk, Ireland) to remove anycolor contaminants that may be remaining in the flake. In variousembodiments, an electro-optical flake sorter based at least in part onRaman technology (e.g., a Powersort 200 from Unisensor SensorsystemeGmbH of Karlsruhe, Germany) may perform a polymer separation to removeany non-PET polymers remaining in the flake. This operation may alsofurther remove any remaining metal contaminants and color contaminants.

In various embodiments, the combination of these steps may deliversubstantially clean (e.g., clean) PET bottle flake comprising less thanabout 50 parts per million PVC (e.g., 25 ppm PVC) and less than about 15parts per million metals for use in the downstream extrusion processdescribed below.

Identifying and Removing Impurities and Impure Flakes

In various embodiments, after the flakes are washed, they are fed down aconveyor and scanned with a high-speed laser system for furthercontaminant removal. In various embodiments, one or more particularlasers may be configured to detect the presence of particularcontaminants (e.g., PVC, aluminum). Flakes that are identified as notconsisting essentially of PET polymer may be blown from the main streamof flakes with air jets. In various embodiments, the resultingproportion of non-PET flakes may be less than 25 ppm.

In various embodiments, the system may be adapted to ensure that the PETpolymer being processed into filament is substantially free of water(e.g., entirely free of water). In a particular embodiment, the flakesare placed into a pre-conditioner for between about 20 and about 40minutes (e.g., about 30 minutes) during which the pre-conditioner blowsthe surface water off of the flakes. In particular embodiments,interstitial water may remain within the flakes. In various embodiments,such “wet” flakes (e.g., flakes comprising interstitial water) may beprocessed using an extruder (e.g., as described in regard to variousembodiments herein) that may include a vacuum setup designed toremove—among other things—the interstitial water that remains present inthe flakes following the relatively quick drying process.

Using an Extrusion System to Melt and Purify PET or PTT Flakes

FIG. 2 depicts an exemplary process flow for producing BCF with an addedcolorant (e.g., liquid colorant, solid colorant, molten liquid polymericmasterbatch, liquid polymeric masterbatch, solid polymeric masterbatch,compounded coloring material, etc.) according to particular embodiments.As shown in FIG. 2, in various embodiments, a suitable primary extruder202 may be used to receive, melt, and purify PTT 200, such as anysuitable PTT 200 prepared in any manner described above. In a particularembodiment, the primary extruder 202 comprises any suitable extrudersuch as, for example, a multiple screw extruder (e.g., a MultipleRotating Screw (“MRS”) extruder such as the MRS extruder described inU.S. Pat. No. 7,513,677, entitled “Extruder for Producing Molten PlasticMaterials,” which is hereby incorporated herein by reference), a twinscrew extruder, a multiple screw extruder, a planetary extruder, or anyother suitable multiple screw extrusion system). An exemplary multiplescrew extruder 400 is shown in FIGS. 3 and 4.

As may be understood from FIGS. 3 and 4, in particular embodiments, themultiple screw extruder includes a first single-screw extruder section410 for feeding material into a multiple screw section 420 and a secondsingle-screw extruder section 440 for transporting material away fromthe MRS section.

As may be understood from FIG. 3, in various embodiments, PET may firstbe fed through the multiple screw extruder's first single-screw extrudersection 410, which may, for example, generate sufficient heat (e.g., viashearing) to at least substantially melt (e.g., melt) the wet flakes.

The resultant polymer stream (e.g., of melted PET), in variousembodiments, may then be fed into the extruder's multiple screw section420, in which the extruder separates the polymer flow into a pluralityof different polymer streams (e.g., 4, 5, 6, 7, 8, or more streams)through a plurality of open chambers. FIG. 4 shows a detailed cutawayview of a multiple screw section 420 according to a particularembodiment. In various embodiments, such as the embodiment shown in thisfigure, the multiple screw section 420 (e.g., MRS section) separates thepolymer flow into eight different streams, which are subsequently fedthrough eight satellite screws 425A-H. As may be understood from FIGS. 3and 4, in particular embodiments, these satellite screws aresubstantially parallel (e.g., parallel) to one other and to a primaryscrew axis of the multiple screw extruder 400.

As shown in FIG. 4, in various embodiments the satellite screws 425A-Hmay be arranged within a single screw drum 428 that is mounted to rotateabout its central axis. The satellite screws 425A-H may be configured torotate in a direction that is opposite to the direction in which thesingle screw drum 428 rotates. In various other embodiments, thesatellite screws 425A-H and the single screw drum 428 may rotate in thesame direction. In various embodiments, the rotation of the satellitescrews 425A-H may be driven by a ring gear. In some particularembodiments, the single screw drum 428 may rotate about four timesfaster than each individual satellite screw 425A-H. In certain otherparticular embodiments, the satellite screws 425A-H rotate atsubstantially similar (e.g., the same) speeds.

In various embodiments, as may be understood from FIG. 4, the satellitescrews 425A-H are housed within respective extruder barrels, which may,for example, be about 30% open to an outer chamber of the multiple screwsection 420. In particular embodiments, the rotation of the satellitescrews 425A-H and single screw drum 428 increases the surface exchangeof the polymer stream (e.g., exposes more surface area of the meltedpolymer to the open chamber than in previous systems). In variousembodiments, the multiple screw section 420 may create a melt surfacearea that is, for example, between about 20 and about 30 times greaterthan the melt surface area created by a co-rotating twin screw extruder.In a particular embodiment, the multiple screw section 420 may create amelt surface area that is, for example, about twenty-five times greaterthan the melt surface area created by a co-rotating twin screw extruder.

In various embodiments, the multiple screw extruder's multiple screwsection 420 may be fitted with a vacuum pump that may be attached to avacuum attachment portion 422 of the multiple screw section 420 so thatthe vacuum pump is in communication with the interior of the multiplescrew section via a suitable opening 424 in the multiple screw section'shousing. In still other embodiments, the multiple screw section 420 maybe fitted with a series of vacuum pumps. In particular embodiments, thevacuum pump is configured to reduce the pressure within the interior ofthe multiple screw section 420 to a pressure that is between about 0.5millibars and about 25 millibars. In other particular embodiments, thevacuum pump is configured to reduce the pressure in the multiple screwsection 420 to less than about 5 millibars (e.g., about 1.8 millibars orless). In other particular embodiments, the vacuum pump is configured toreduce the pressure in the multiple screw section 420 to between about 0millibar and about 1.5 millibars (e.g., between about 0 millibar andabout 1 millibar). In other particular embodiments, the vacuum pump isconfigured to reduce the pressure in the multiple screw section 420 tobetween about 0.5 millibars and about 1.2 millibars. In other particularembodiments, the vacuum pump is configured to reduce the pressure in themultiple screw section 420 to between about 0 millibar and about 5millibars. In a particular embodiment, the vacuum pump used withextruder 400 is a jet vacuum pump is made by Arpuma GmbH of Bergheim,Germany.

The low-pressure vacuum in the multiple screw section 420 created by thevacuum pump in the multiple screw section 420 (e.g., MRS section) mayremove, among other things, volatile organics present in the meltedpolymer as the melted polymer passes through the multiple screw section420 and/or at least a portion of any interstitial water that was presentin the wet flakes when the wet flakes entered the extruder 400. Invarious embodiments, the low-pressure vacuum removes substantially all(e.g., all) of the water and contaminants from the polymer stream.

In some embodiments, after the molten polymer is run the through themultiple screw section 420, the streams of molten polymer may berecombined and flow into the multiple screw extruder's second singlescrew section 440. In various embodiments, the resulting single streamof molten polymer may next be run through a filtration system thatincludes at least one filter. Such a filtration system may include twolevels of filtration (e.g., a 40 micron screen filter followed by a 25micron screen filter). Although, in various embodiments, water andvolatile organic impurities are removed during the vacuum process asdiscussed above, particulate contaminates such as, for example, aluminumparticles, sand, dirt, and other contaminants may remain in the polymermelt. Thus, this filtration step may be advantageous in removingparticulate contaminates (e.g., particulate contaminates that were notremoved in the multiple screw section 420).

In particular embodiments, a viscosity sensor may be used to sense amelt viscosity of the molten polymer stream, for example, following itspassage through the filtration system. The system may utilize theviscosity sensor to measure the melt viscosity of a stream, for example,by measuring the stream's pressure drop across a known area. Inparticular embodiments, in response to measuring an intrinsic viscosityof the stream that is below a predetermined level (e.g., below about 0.8g/dL), the system may discard the portion of the stream with lowintrinsic viscosity and/or lower the pressure in the multiple screwsection 420 in order to achieve a higher intrinsic viscosity in thepolymer melt. In particular embodiments, decreasing the pressure in themultiple screw section 420 is executed in a substantially automatedmanner (e.g., automatically) using the viscosity sensor in acomputer-controlled feedback control loop with the vacuum pump.

Removing the water and contaminates from the polymer may improve theintrinsic viscosity of the recycled PET polymer by allowing polymerchains in the polymer to reconnect and extend the chain length. Inparticular embodiments, following its passage through the multiple screwsection 420 as operated in conjunction with an attached vacuum pump,recycled polymer melt has an intrinsic viscosity of at least about 0.79dL/g (e.g., of between about 0.79 dL/g and about 1.00 dL/g). Inparticular embodiments, passage through a low pressure multiple screwsection 420 purifies the recycled polymer melt (e.g., by removing thecontaminants and interstitial water). In particular embodiments, thewater removed by passing through a lowered pressure environment includesboth water from the wash water used to clean the recycled PET bottles asdescribed above, as well as from unreacted water generated by themelting of the PET polymer in, for example, the first single-screwextruder section 410 (e.g., interstitial water). In some embodiments,the majority of water present in the polymer is wash water, but somepercentage may be unreacted water.

In particular embodiments, passage through the low pressure multiplescrew section 420 purifies the recycled polymer stream (e.g., byremoving the contaminants and interstitial water) and makes the recycledpolymer substantially structurally similar to (e.g., structurally thesame as) pure virgin PET polymer. In particular embodiments, theresulting polymer is a recycled PET polymer (e.g., obtained 100% frompost-consumer PET products, such as PET bottles or containers) having apolymer quality that is suitable for use in producing PET carpetfilament using substantially only (e.g., only) PET from recycled PETproducts.

Operation 2: Adding a Colorant to the Polymer Stream Downstream from thePrimary Extruder

In particular embodiments, after the recycled PET polymer, virgin PET,or PTT has been extruded and purified by the above-described extrusionprocess, a colorant (e.g., liquid colorant, solid colorant, moltenliquid polymeric masterbatch, liquid polymeric masterbatch, solidpolymeric masterbatch, compounded coloring material, etc.) may be addedto the resultant polymer stream. FIG. 2 shows a polymer stream of PTT200 passing through a primary extruder 202 before Colorant A 204 and PET220 are added via a secondary extruder 206. FIG. 2 is equally applicableto implementations in which the polymer stream being processed is PET220.

The secondary extruder 206 may include any suitable extruder such as forexample, any suitable single-screw extruder, multiple screw extruder, orother extruder described herein (e.g., a twin screw extruder, aplanetary extruder, or any other suitable extrusion system). Inparticular embodiments, a suitable secondary extruder 206 may include,for example, an HPE-150 Horizontal Extruder manufactured byDavid-Standard, LLC of Pawcatuck, Conn. In other particular embodiments,a suitable secondary extruder 206 may include, for example, an MRSextruder.

Colorant A 204 may include a solid colorant, such as pelletized colorconcentrate, solid polymeric masterbatch, or solid compounded coloringmaterial, which the secondary extruder 206 may be configured to at leastpartially melt prior to adding Colorant A 204 to the polymer stream. Invarious other embodiments, Colorant A 204 may comprise other additivessuch as, for example, a carrier resin which may aid in binding thecolorant to the polymer. In other embodiments, Colorant A 204 mayinclude any suitable liquid colorant, such as liquid color concentrate,liquid polymeric masterbatch, or liquid compounded coloring material,which may be pumped into the polymer stream using any suitable pump(e.g., in lieu of using a secondary extruder 206 and a solid colorant).

In various embodiments, the process may further include monitoring anamount of throughput (e.g., polymer output) from the primary extruder202 in order to determine an appropriate amount of letdown (e.g., anappropriate letdown ratio) such that a proper amount of Colorant A 204may be added to the polymer stream downstream from the primary extruder202. In various embodiments, a desirable letdown ratio may include aletdown ratio of between about one tenth of one percent and about eightpercent (e.g., about two percent). In other embodiments, the letdownratio may include any other suitable letdown ratio (e.g., one percent,two percent, three percent, four percent, five percent, six percent,seven percent, etc.). In particular embodiments, the letdown ratio mayvary based on a desired color of BCF ultimately produced using theprocess (e.g., up to about twenty percent).

In various embodiments, adding the colorant 204 downstream of theprimary extruder 202 may save on waste during color changeover. Forexample, when switching between producing BCF of a first color toproducing BCF of a second color, it may be necessary to change thecolorant 204 added to the polymer stream (e.g., from a first colorantthat would result in BCF of the first color to a second colorant thatwould result in BCF of the second color). As will be understood by oneskilled in the art, after switching from adding the first colorant tothe polymer stream to adding the second colorant to the polymer stream,residual first colorant may remain in in the system between the point inthe process at which the colorant is added and the spinning machine 212.For example, residual first colorant may remain in the secondaryextruder 206, the one or more static mixing assemblies 208, or any otherphysical mechanism used in the process (such as any mechanism shown inFIG. 2) or any piping or tubing which connects the various components ofthe system.

As will be understood by one skilled in the art, after running theprocess with the second colorant for a suitable amount of time, the BCFproduced by the process will eventually be of the second, desired color(e.g., because the first colorant will eventually be substantiallyflushed out the system). However, between the point at which there is achangeover in adding the second colorant to the process rather than thefirst colorant and the point at which the process begins to produce thedesired color of BCF, the process may produce some waste BCF that is ofan undesired color (e.g., due at least in part to the residual firstcolorant).

In various embodiments, the waste BCF produced using the processdescribed herein may be considerably lower than waste BCF producedduring color changeovers using other processes (e.g., such as otherprocesses in which colorant is added to PET prior to extrusion in aprimary extruder such as an MRS extruder). For example, in variousembodiment, the process described herein may limit waste BCF to anamount of BCF produced when running a single package of colorant (e.g.,of the second colorant), which may, for example, result in less thanabout 100 pounds of waste. In particular embodiments, reducing waste inthis manner may lead to cost saving in the production of BCF.

Operation 3: Adding PET to the Extruded Polymer Stream

According to an embodiment shown in FIG. 2, the polymer stream beingprocessed is a PTT 200 polymer stream. In this example, rather thanadding the desired quantity of PET 220 to the primary extruder 202, asconventionally done, the PET 220 may be added to the secondary extruder206 (e.g., only, without colorant). In another example, rather thanadding the desired quantity of PET 220 to the primary extruder 202, thePET 220 may be added to the secondary extruder 206 with the Colorant A204. These configurations may be especially advantageous when there isother equipment or production line configuration issues that extend thelength of the production line to a degree that would create excessivehold up times resulting in undesirable transesterification if the PET220 were added at the primary extruder 202 rather than downstream at thesecondary extruder 206, as shown in FIG. 2. The addition of PET into astream of PTT will be discussed in further detail with respect toembodiments shown in FIGS. 11 and 12. Structural aspects of a polymerinjection port for providing PET 220 into the polymer stream of PTT 200will be described with respect to FIGS. 15 and 17A-17C.

Operation 4: Using One or More Static Mixing Assemblies to Mix PolymerStream with Added Colorant

In particular embodiments, following the addition of the Colorant A 204to the stream of molten polymer, the process may include the use of oneor more static mixing assemblies 208 (e.g., one or more static mixingelements) to mix and disperse the Colorant A 204 throughout the polymerstream. As may be understood by one skilled in the art, due in part tothe viscosity of the polymer stream (e.g., polymer stream), when a dyeor other colorant is added to the polymer stream, the dye and the streammay not mix. In various embodiments, the flow of the polymer stream issubstantially laminar (e.g., laminar) which may, for example, furtherlead to a lack of mixing. FIG. 5 depicts a cross section view of apolymer stream conduit 500 containing a polymer stream 510 into which acolorant 520 has been added. As shown in this figure, the colorant 520has not mixed with the polymer stream 510. Generally speaking, theunmixed polymer stream 510 and colorant 520 may not be suitable forforming into BCF (e.g., because the resulting filament may not have aconsistent, uniform color). FIG. 6 depicts the polymer stream conduit500 of FIG. 5 in which the colorant 520 and the polymer stream 510 havebeen (e.g., uniformly) mixed into a colored polymer stream 530. Thissubstantially uniform mixing, in various embodiments, is achievedthrough the use of one or more static mixing assemblies, such as the oneor more static mixing assemblies 208 shown in FIG. 2. Generallyspeaking, this uniformly mixed colored polymer stream 530 shown in FIG.5 may be far more suitable for producing uniformly colored BCF.

FIG. 7 depicts an exemplary static mixing element 700 which may, invarious embodiments, be utilized in the achievement of substantiallyuniform (e.g., uniform) mixing of the polymer stream and the addedcolorant (e.g., Colorant A 204 from FIG. 2). As may be understood fromthis figure, a static mixing element 700 may comprise a housing 702(e.g., a substantially circular or cylindrical housing) and be insertedinto a polymer stream conduit or other housing (e.g., incorporated intoa polymer stream conduit or other housing). In the embodiment shown inthis figure, the static mixing element 700 may include a plurality ofmixing bars 704 disposed within the housing 702. In particularembodiments, the static mixing element 700 creates mixing by directingtwo or more viscous materials to follow the geometric structure of themixing bars 704 disposed within the housing 702 that continuously divideand recombine the flow. In various embodiments, a very high degree ofmixing may be achieved over a short length of static mixing elements. Inparticular embodiments, the static mixing element 700 may include nomoving parts and may be made of any suitable material, such as, forexample, high strength heat treated stainless steel, a suitable plastic,or any other suitable material.

In particular embodiments, the static mixing assemblies 208 shown inFIG. 2 may comprise any suitable static mixing element, such as, forexample, a Stamixco GXR 40/50 or GXR 52/60 made by Stamixco LLC ofBrooklyn, N.Y. A suitable mixing element for use as, or within, a staticmixing assembly is described in U.S. Pat. No. 8,360,630, entitled“Mixing Elements for a Static Mixer and Process for Producing Such aMixing Element,” which is hereby incorporated herein in its entirety. Inother embodiments, the one or more static mixing assemblies 208 maycomprise any other suitable static mixing element having a suitablearrangement of mixing bars for dispersing the colorant throughout thepolymer stream. In particular embodiments, the one or more static mixingassemblies 208 may include a plurality of individual static mixingelements such as individual static mixing elements 700 shown in FIG. 8.FIG. 8 depicts eight static mixing elements 700 a-h coupled to oneanother to form a static mixing assembly 208. In other embodiments, thestatic mixing assemblies 208 may include any suitable number ofindividual static mixing elements 700 (e.g., up to 36 or 40 individualstatic mixing elements). In particular embodiments, the individualstatic mixing elements 700 may be oriented in any suitable directionrelative to one another (e.g., oriented randomly relative to one anotherwhen coupled to one another as shown in FIG. 8). In other embodiments,the static mixing elements may be oriented such that they alternate ahorizontal and vertical alignment relative to one another. In stillother embodiments, each adjacent static mixing element is substantiallyperpendicular to the adjacent static mixing element. In still otherembodiments, the individual static mixing elements may be arranged inany suitable unaligned or aligned manner.

In various other embodiments, the static mixing assemblies 208 mayinclude a suitable number of static mixing elements comprising one ormore suitable helical mixing elements. FIG. 9 depicts an exemplaryhelical static mixing assembly 900 that may be configured with asubstantially cylindrical (e.g., cylindrical) housing 902 in which atleast one helical mixing element 904 may be disposed. As shown in thisfigure, the at least one helical mixing element 904 may define a leadingedge 906 that extends between opposing interior portions of thecylindrical housing 902 (e.g., along a diameter of the cylindricalhousing 902). In various embodiments, the leading edge 906 may besubstantially planar (e.g., linear) and may have any suitable thickness.As may be understood from this figure, the leading edge 906 may divide(e.g., bisect) a polymer stream flowing into the helical static mixingassembly 900 into two streams (e.g., a first stream on a first side ofthe leading edge 906 and a second stream on a second side of the leadingedge 906). In particular embodiments, the leading edge 906 may dividethe flow into substantially equal streams as material passes the helicalmixing element 904.

FIG. 10 depicts the helical static mixing assembly 900 of FIG. 9 in acutaway view that shows the four helical mixing elements 904 that may bedisposed within the housing 902. As may be further understood from FIG.10, each individual helical mixing element 904 (e.g., helical mixingelement 904 a) may be constructed of a substantially rectangular (e.g.,rectangular) plate defining a leading edge 906 a and a trailing edge 908a that has been twisted about 180 degrees (e.g., 180 degrees). As shownin this figure, the leading edge 906 a and trailing edge 908 a ofhelical mixing element 904 a are substantially parallel (e.g., parallel)to one another. Also as shown, the helical mixing element 904 a extendsbetween the leading edge 906 a and trailing edge 908 a in a helicalshape. Although shown in this figure as having a twist of 180 degreesbetween the leading edge 906 a and trailing edge 908 a, it should beunderstood that in various other embodiments, the helical mixing element904 a, and each of the individual helical mixing elements 904, may haveany other suitable helical shape or portion thereof. For example, inparticular embodiments, the one or more of the helical mixing elements904 may comprise a substantially rectangular plate defining a leadingedge 906 and a trailing edge 908 that has been twisted any othersuitable amount between zero and 360 degrees (e.g., 45 degrees, 90degrees, 270 degrees, etc.) In still other embodiments, one or more ofthe helical mixing elements 904 may have any suitable length relative toits diameter.

As may be further understood from FIG. 10, in various embodiments, eachparticular helical mixing element 904 a-d may be disposed within thehousing 902 at an angle to an adjacent helical mixing element 904. Forexample, helical mixing element 904 a may be disposed such that atrailing edge 908 a of helical mixing element 904 a forms an angle withthe leading edge 906 b of helical mixing element 906 b. In particularembodiments, the trailing edge 908 a and leading edge 906 b of adjacenthelical mixing elements 904 may form any suitable angle with oneanother. In particular embodiments, the trailing edge 908 a and leadingedge 906 b of adjacent helical mixing elements 904 may form an angle ofbetween about zero degrees and about ninety degrees with one another. Inparticular embodiments, the trailing edge 908 a and leading edge 906 bof adjacent helical mixing elements 904 may at least partially abut oneanother and be substantially co-facing (e.g., co-facing). In particularembodiments, the trailing edge 908 a and leading edge 906 b of adjacenthelical mixing elements 904 may form a particular angle between oneanother (e.g., zero degrees, ninety degrees, forty-five degrees, or anyother suitable angle). A suitable helical static mixing assembly for usein the above-described process may include, for example, a suitablehelical static mixing assembly manufactured by JLS International ofCharlotte, N.C.

It should be understood that for the purposes of this disclosure, astatic mixing assembly 208 may be configured in any desired arrangementthat may provide a desired number of one or more individual mixingelements to a polymer stream. For example, a static mixing assembly 208may include a single mixing element within a single housing with one ormore mixing bars 704 and/or one or more helical mixing elements 904disposed within the housing. Alternatively, the static mixing assembly208 may include multiple static mixing elements positioned in serieswithin a single housing. According to yet another alternativeembodiment, the static mixing assembly 208 may include a plurality ofstatic mixing elements, each having their own respective housingpositioned in series adjacent to one another. In this embodiment, theplurality of static mixing elements is collectively considered thestatic mixing assembly 208. For example, in particular embodiments, thestatic mixing assembly 208 comprises up to 36 individual static mixingelements (e.g., 36 static mixing elements, 34 static mixing elements,etc.). In still other embodiments, the static mixing assembly 208 mayinclude any other suitable number of static mixing elements sufficientto substantially uniformly (e.g., homogeneously) mix the molten polymerwith the added colorant (e.g., to substantially uniformly mix the moltenpolymer and the added colorant into a colored polymer stream 530 asshown in FIG. 6). This may include, for example, up to 40 static mixingelements, or any other suitable number).

In particular embodiments, the one or more static mixing assemblies 208may comprise any suitable combination of static mixing elements such as,for example, any suitable break down of the static mixing element 700shown in FIG. 7 and the helical static mixing assembly 900 and/orhelical mixing elements 904 shown in FIGS. 9 and 10. For example, in aparticular embodiment, the static mixing assemblies 208 may include 36helical mixing elements 904. In other embodiments, the static mixingassemblies 208 may include 36 static mixing elements 700 from FIG. 7. Invarious embodiments, the static mixing assemblies 208 may comprise anysuitable number of alternating static mixing elements 700 shown in FIG.7 and helical mixing elements 904 shown in FIGS. 9 and 10. In variousother embodiments, the static mixing assemblies 208 may have up to atotal of forty (e.g., 36), or more, individual static mixing elements700 shown in FIG. 7 and helical mixing elements 904 shown in FIGS. 9 and10. In such embodiments, the static mixing elements 700 from FIG. 7 andthe helical mixing elements 904 may be arranged and combined in anysuitable order and manner (e.g., a specific order, a random order, apattern such as a repeating pattern, etc.).

Creating a Tonal Color in Polymer Stream

According to various embodiments, it may be desirable to create BCF foruse in the production of carpet and other products that is not uniformin color. Specifically, it may be desirable to create BCF that has atonal color effect. For the purposes of this disclosure, BCF having atonal color effect may include BCF having any color that is not uniform,such as BCF that includes different shades of the same color (e.g., withgradual changes between one shade to another). Conventionally, tonalcolor effects may be created using one or more yarns or filaments havingone dark end and one light end, which are twisted together to create atonal yarn. However, using the concepts and technologies describedherein, a tonal color effect may be created using a single yarn, withoututilizing a conventional twisting process.

According to various embodiments, a tonal effect characteristic of thepolymer stream and resulting BCF product may be created using a smallernumber of static mixing elements (e.g., individual static mixingelements 700, helical mixing elements 904) as compared to the at least30 individual static mixing elements utilized to create the uniformlymixed and uniformly colored polymer streams described elsewhere herein.For example, in some embodiments, a smaller number of individual staticmixing elements 700 or helical static mixing elements 904 (e.g., anydiscrete number less than 30) may be used to create the static mixingassemblies 208 of FIG. 2. By using a relatively small number ofindividual static mixing elements, in various embodiments, the colorantinjected into the laminar flow of the polymer stream traversing throughthe static mixing assemblies 208 may not be uniformly mixed into thepolymer stream prior to being received by the spinning machine 212.

While, in various embodiments, providing a static mixing assembly 208with fewer individual static mixing elements (e.g., static mixingelements 700, helical static mixing elements 904) may create a tonalcolor characteristic in the resulting polymer stream, variousembodiments described herein may produce tonal color effects, whileallowing for the same BCF manufacturing system to be utilized to createboth uniformly-colored BCF and BCF having tonal color effects with, invarious embodiments, minimal time and effort in changing the system setup between manufacturing runs of the two products.

Turning to FIG. 13, an exemplary static mixing assembly 208 is shownhaving a number of individual static mixing elements 700 or 904 coupledtogether to create a length of the static mixing assembly 208 throughwhich the polymer stream flows and mixes. It should be appreciated thatfor clarity purposes, the static mixing assembly 208 is shown with areduced quantity of individual static mixing elements 700 or 904 shownin FIG. 13. As disclosed herein, the static mixing assembly 208 ofvarious embodiments may have more than 30 (e.g., 36, 40) individualstatic mixing elements 700 or 904.

According to various embodiments, the static mixing assembly 208 mayhave one or more color injection assemblies 1302 a-n (collectivelyreferred to as color injection assemblies 1302 or color injection ports1302), and/or liquid injection nozzles, positioned along a length of thestatic mixing assembly 208. The one or more color injection assemblies1302 may include any type of port suitable for facilitating theinjection of colorant from one or more color probes 1304 into thepolymer stream within the static mixing assembly 208. According to oneembodiment, the one or more color injection assemblies 1302 includethreads for receiving the one or more color probes 1304 and/or one ormore mechanisms coupled to the one or more color probes 1304. In otherembodiments, the one or more color injection assemblies 1302 and the oneor more color probes 1304 may be coupled together via a quick disconnectconnection 1306 that allows for easy and rapid connection of the one ormore color probes 1304 to/from the color injection assemblies 1302.Various features of color injection assemblies 1302 according to variousembodiments will be described in detail below with respect to FIGS. 15and 16A-16C.

Once a color probe 1304 is connected to a respective color injectionassembly 1302, colorant may be injected from the probe, through the portand into a location that is substantially at a centered position of thepolymer stream within the static mixing assembly 208, a locationproximate to an inside wall of the housing of the static mixing assembly208 (e.g., housing 702), and/or any other suitable location. Injectingcolorant into the center of the polymer stream may result in moreuniform mixing, while injecting the colorant into the polymer streamproximate to a wall of the static mixing assembly's 208 housing 702 mayyield more distinct tonal color effects in the resulting colored polymerstream and corresponding BCF product.

FIG. 13 shows three pairs of color injection assemblies 1302 a, 1302 b,1302 n positioned in three different locations along the length of thestatic mixing assembly 208 and four individual color injectionassemblies 1302 c, 1302 d, 1302 e, 1302 f. It should be appreciated thatany number of color injection assemblies 1302 may be used at eachrespective distance along the length of the static mixing assembly 208and that groups of one or more color injection assemblies 1302 may bepositioned at any respective distance along the length of the staticmixing assembly 208 without departing from the scope of this disclosure.In particular embodiments, one or more color injection ports arepositioned between each of at least 2, 3, 4, 5, 6, 7, or 8 consecutiverespective adjacent pairs of mixing elements within the mixing assembly.

For example, while the one or more of the color injection assemblies1302 are shown in pairs at some locations (pairs of color injectionassemblies 1302 a, 1302 b, 1302 n), various embodiments may utilize onlya single color injection assembly 1302 at each location, or mayalternatively utilize more than two color injection assemblies 1302 ateach location along the length of the static mixing assembly 208. Invarious embodiments, the positioning of the one or more color injectionassemblies 1302 around the circumference of the static mixing assembly208 may differ. For example, a first color injection assembly 1302 a maybe positioned on a top side (i.e., at the zero degree location whenviewing the circular cross-section) of the static mixing assembly 208,while a second color injection assembly 1302 b that is locateddownstream along the length of the static mixing assembly 208 may bepositioned on the right side (i.e., at the 90 degree location whenviewing the circular cross-section) of the static mixing assembly 208.The various radial positionings of color injection ports/assemblies 1302around the circumference of the static mixing assembly 208 may yielddifferent tonal color effects in the colored polymer stream exiting thestatic mixing assembly 208 if the colorant is injected within thepolymer stream at a location other than centrally (e.g., proximate tothe wall of the housing of the static mixing assembly 208).

The static mixing assembly 208 shown in FIG. 13 has one or more colorinjection assemblies 1302 positioned at the upstream end 1308 of thestatic mixing assembly 208 where the polymer stream may enter. Asdescribed above, providing colorant at the upstream end 1308 may resultin a uniform mix and corresponding uniformly colored polymer streamexiting the downstream end 1310 of the static mixing assembly 208.However, if colorant is added at locations downstream of the upstreamend 1308, less mixing of the colorant with the polymer stream may occur,resulting in a tonal color effect. As discussed, colorant added at theone or more color injection assemblies 1302 n positioned within 5 to 20individual static mixing elements from the downstream end 1310 of thestatic mixing assembly 208, the resulting colored polymer stream is mostlikely to possess distinct tonal color effects that may be formed into atonal yarn using one or more spinning machines 212.

In various embodiments, multiple color probes 1304 (e.g., that may beconfigured to selectively deliver liquid colorant under pressure—e.g.,via a suitable pump arrangement, such as any suitable pump arrangementdescribed below) may be utilized simultaneously with multiplecorresponding color injection assemblies 1302 at different locationsalong the length of the static mixing assembly 208 to create tonal coloreffects with multiple colors. For example, a first color probe 1304having a first color may be coupled to the color injection assembly 1302b, while a second color probe 1304 having a second color may be coupledto the color injection assembly 1302 n. The resulting colored polymerstream may contain tonal color effects with respect to the first colorthat are more subtle than the tonal color effects associated with thesecond color that are present in the same colored polymer stream. Thismay occur because the polymer stream is injected with the first color(e.g., by color injection assembly 1302 b) for a longer period of timethan the colored polymer stream (containing a mix with the first color)is injected with the second color (e.g., by color injection assembly1302 n).

Alternatively, according to another embodiment, a first color probe 1304having a first color may be coupled to the color injection assembly 1302n shown on the top side of the static mixing assembly 208, while asecond color probe 1304 having a second color may be coupled to thecolor injection assembly 1302 n shown on the bottom side of the staticmixing assembly 208. In this embodiment, two different colorants areinjected into the polymer stream at different radial locations aroundthe circumference of the static mixing assembly 208. Doing so may allowthe polymer stream, the first colorant, and the second colorant to mixfor a short length prior to exiting the downstream end 1310 of thestatic mixing assembly 208 with a unique tonal color effect.

FIG. 14 depicts a high-level overview of BCF manufacturing process 1400for producing and coloring BCF with a tonal color effect, for example,for use in the production of carpet and other products. The process 1400may begin as described above with respect to operations 102 and 104 ofFIG. 1 above. Specifically, at operation 1402, PET, PTT, or otherpolymer flakes are passed through an extruder that melts the flakes andpurifies the resulting polymer. At operation 1404, the extruded polymerstream may then be optionally split into a plurality of polymer streams.

At operation 1406, PET 220 may be added to the polymer stream downstreamof the primary extruder 202 if the polymer stream is PTT 200. One ormore static mixing assemblies 208 may be used to mix each of the polymerstreams at operation 1408. Colorant (e.g., liquid colorant, solidcolorant, molten liquid polymeric masterbatch, liquid polymericmasterbatch, solid polymeric masterbatch, compounded coloring material,etc.) may be added at operation 1410 to the one or more static mixingassemblies 208 through one or more color injection assemblies 1302. Theone or more color injection assemblies 1302 that are used for injectingcolorant may be selected based on the location of the one or more colorinjection assemblies 1302 along the length of the one or more staticmixing assemblies 208. The locations of the one or more color injectionassemblies 1302 may determine the amount of mixing of the one or morecolorants with the polymer stream within the static mixing assembly 208and/or the desired tonal color effect of the resulting BCF product. Atoperation 1412, each of the polymer streams with the desired tonal coloreffects are fed into a respective spinning machine 212 to turn thepolymer into a tonal filament for use in manufacturing carpets or otherproducts.

Turning now to FIG. 15, an illustrative example of a color injectionassembly 1302 will be described. FIG. 15 shows a cross-sectional view ofa polymer stream conduit 1502 with a color injection port 1510 and apolymer injection port 1508 for providing liquid colorant and PET 220,respectively, to a polymer stream of PTT 200 (e.g., or for providingliquid colorant to a polymer stream of PET or other suitable polymer orcombination of polymers). According to this example, the polymer streamconduit 1502 includes both an inner and outer shell. The polymer streamof PTT 200 may flow through the inner shell of polymer stream conduit1504 (e.g., away from the viewer, into the page). A heat transfer liquid1507 may flow between the inner shell 1504 and the outer shell of thepolymer stream conduit 1502. In a particular embodiment, a suitable heattransfer liquid 1507 that may be used is DOWTHERM “A” from The DowChemical Company of Midland, Mich. The heat transfer liquid 1507 may becontrolled to keep the PTT 200 within the inner shell 1502 at adetermined or desired temperature. In particular embodiments, the PTT200 flows at approximately 260° C. at a pressure of approximatelybetween about 1000 psi and about 1200 psi.

In particular embodiments, a flange 1512 (e.g., which may be downstreamfrom a pump) or other suitable mechanism may control a flow of heattransfer liquid 1507 between the inner shell 1504 and the outer shell1502. The polymer injection port 1508 may include a polymer inlet tube1514 that extends into the interior portion of the polymer stream todeliver the PET 220 into the PTT 200. The polymer injection port 1508will be described in greater detail below with respect to FIGS. 17A-17B.

The right portion of FIG. 15 illustrates an example color injectionassembly 1302 configured to engage a color injection probe 1304containing the liquid colorant and to position the color probe 1304within the polymer stream. From this position within the interiorportion of the polymer stream, the liquid colorant is released from theoutlet end of a stream engagement portion 1516 of the color injectionprobe 1304 and into the polymer stream. According to one embodiment, theliquid colorant is introduced to the polymer stream at a centeredposition of the polymer stream that is substantially equidistant fromall walls of the inner shell of the polymer stream conduit 1504.

By injecting the liquid colorant into the center of the polymer stream,the efficiency of the mixing within the downstream static mixingassembly is maximized. As stated above, the static mixing assembly 208of various embodiments may have more than 30 (e.g., 36, 40) individualstatic mixing elements 700, 904. Consequently, due to this relativelylarge number of individual static mixing elements 700, 904, as well asthe orientation of the elements, one would expect a similar andconsistent mixing quality of the colorant with the polymer streamregardless of the position within the polymer stream in which the liquidcolorant is injected upstream of the static mixing assembly 208.However, tests have shown an unexpected result that the most uniform andconsistent mixing quality occurs when the liquid colorant is injected ina centered position within the polymer stream that is substantiallyequidistant from the walls of the inner shell of the polymer streamconduit 1504. To achieve injection at this centered location, the streamengagement portion 1516 of the color injection assembly 1302 extendsinto the interior portion of the polymer stream to a position adjacentto the centered position of the polymer stream so that the pressurizedcolorant exiting the color injection probe 1304 flows into thepressurized polymer stream at substantially the centered position of thepolymer stream conduit 1502.

Similarly, in particular embodiments, the PET 220 may be injected intothe centered position of the polymer stream that is substantiallyequidistant from all walls of the inner shell of the polymer streamconduit 1504. In the example shown in FIG. 15, the PET 220 is injectedat substantially a same position along a length of a polymer streamconduit encompassing the polymer stream. As seen in this example, thepolymer inlet tube 1514 of the polymer injection port 1508 and thestream engagement portion 1516 of the color injection assembly 1302 areconfigured on opposing sides of the polymer stream conduit 1502. Byinjecting the liquid colorant and the PET 220 into the center of thepolymer stream at the same location prior to or at the static mixingassembly 208, a relatively short hold up time preventstransesterification of the PET 220 and PTT 200 mixture, while maximizingthe efficiency of the color mixing through the static mixing assembly208.

According to various embodiments, the color injection assembly 1302 mayinclude a color injector housing 1510 that couples the color injectionassembly 1302 to the polymer stream conduit 1502. The color injectorhousing 1510 may at least partially encompass a color probe channel 1526extending through the color injection assembly 1302. The color probechannel 1526 engages the color injection probe 1304 and provides a routefor the corresponding liquid colorant out of the color injection probe1304 and into the polymer stream. The color probe channel 1526 extendsfrom the stream engaging portion 1516, through a pressure blockingmechanism 1524, and through a plunger guide 1522 and correspondingplunger 1520. The plunger 1520 engages the color probe 1304 via threadsor other fastening mechanism. The plunger guide 1522 is configured toguide the plunger 1520 and corresponding color injection probe 1304through the color injection assembly 1302 to the stream engaging portion1516 for delivery of the liquid colorant to the polymer stream.

It is noted that, when color injection is not desired, the colorinjection probe 1304 may be removed from the color injection assembly1302. However, by simply removing the color injection probe 1304 fromthe color injection assembly 1302 without taking further actions, thecolor probe channel 1526 remains vacant creating an opening into whichthe PTT 200 may flow rather than remaining in the polymer stream conduit1502. This may result in hindered flow of PTT 200, clogging of the colorprobe channel 1526 (which may require maintenance to address), andwasted PTT 200. To prevent this, a color probe channel plug may beinserted into the color probe channel 1526. The color probe channel plugmay have an exterior shape that is substantially the same shape and sizeas the color injection probe 1304. In various embodiments, the colorprobe channel plug may have a substantially solid exterior and theexterior may comprise any suitable material to help to create a sealbetween the plug and the color probe channel 1526 to prevent PTT 200from flowing into the color probe channel 1526 while the plug isoperably disposed within the color probe channel 1526.

FIG. 16A shows a side view of the color injection assembly 1302 in aclosed configuration 1602 with the color injection probe 1304 in aretracted position, according to particular embodiments. FIG. 16B showsthe same view of the color injection assembly 1302 in an openconfiguration 1604 with the color injection probe 1304 in a deployedposition. In the closed configuration 1602, the color injection assembly1302 is fluidly decoupled from the polymer stream to prevent the polymerstream at the polymer stream pressure from entering the color injectionassembly 1302.

The pressure blocking mechanism 1524 activates and deactivates tofluidly couple and decouple the color probe channel 1526 of the colorinjection assembly 1302 to the polymer stream. When fluidly coupled tothe polymer stream, the color injection assembly 1302 may provide liquidcolorant from the color injection probe 1304 into the polymer stream viathe color probe channel 1526. When fluidly decoupled from the polymerstream, the color injection assembly 1302 is prevented from providingliquid colorant from the color injection probe 1304 to the polymerstream since the color probe channel 1526 is fluidly disconnected, orblocked, from the polymer stream.

To effectuate this selective coupling and decoupling, the pressureblocking mechanism 1524 may utilize any suitable method for providing abarrier between the polymer stream pressure within the polymer streamconduit 1502 and the pressure on the side of the pressure blockingmechanism 1524 opposite the polymer stream conduit 1502. For example,the pressure blocking mechanism 1524 may utilize a gate, pressure door,or a plug that closes over the color probe channel 1526 or otherwisefills the color probe channel 1526 when the color probe 1304 isretracted in order to prevent the polymer stream at the polymer streampressure from entering the plunger guide 1522.

According to various embodiments, the pressure blocking mechanism 1524is configured as a cylindrical pressure barrier 1612 that includes acolor probe passage 1606. The color probe passage 1606 is substantiallysimilar to the color probe channel 1526 of the color injection assembly1302 so that when the color probe passage 1606 is aligned with the colorprobe channel 1526, the color injection probe 1304 may be retracted anddeployed through the cylindrical pressure barrier 1612 along the lengthof the color injection assembly 1302 to transition between closed andopen configurations 1602 and 1604, respectively.

FIG. 16A shows the color injection assembly 1302 in a closedconfiguration 1602 with the color probe 1304 in a retracted position.FIG. 16B shows the color injection assembly 1302 in an openconfiguration 1604 with the plunger 1520 with corresponding color probe1304 in a deployed configuration. The cylindrical pressure barrier 1612is rotatable between open and closed positions. A rotation mechanism1608 is used to rotate the cylindrical pressure barrier 1612. Therotation mechanism 1608 may include a hex nut or other projection orrecession that has features that may be engaged by a corresponding toolto mechanically apply torque turn the rotation mechanism 1608 andconnected cylindrical pressure barrier 1612. The rotation mechanism 1608may be manually operated or may be connected to a controller (not shown)that provides control signals to activate or deactivate the rotationmechanism 1608 in response to a feedback loop that provides a colorprobe replacement instruction due to a low quantity of liquid colorantwithin the color probe 1304.

In a closed position, as shown in FIG. 16A, the cylindrical pressurebarrier 1612 may be rotated so that the color probe passage 1606 is notaligned with the color probe channel 1526 and the outer wall of thecylindrical pressure barrier 1612 creates a pressure barrier that blocksthe color probe channel 1526 to prevent the polymer stream at thepolymer stream pressure from entering the color injection assembly 1302beyond the cylindrical pressure barrier 1612. In an open position, asshown in FIG. 16B, the cylindrical pressure barrier 1612 may be rotatedso that the color probe passage 1606 aligns with the color probe channel1526 of the color injection assembly 1302. The color probe 1304 can beseen extending through the color probe passage 1606 of the cylindricalpressure barrier 1612 when the color injection assembly 1302 is in theopen configuration 1604.

The color injection probe 1304 may be engaged with the plunger 1520. Thecolor injection probe 1304 may be threaded into the plunger 1520 orsecured in the plunger 1520 using any suitable fastening mechanism. Theplunger 1520 with the color injection probe 1304 secured within may bemoved toward and away from the cylindrical pressure barrier 1612 withinthe probe guide 1522, in and out of the color probe channel 1526. Thismovement may be effectuated using a translation mechanism 1610. Thetranslation mechanism 1610 may include threads so that the plunger 1520and color injection probe 1304 are screwed into and out of the plungerguide 1522. Alternatively, or additionally, the translation mechanism1610 may include any hydraulic, pneumatic, electro-mechanical, ormechanical mechanisms that may be configured to slide or screw theplunger 1520 and color injection probe 1304 into and out of the plungerguide 1522. The translation mechanism 1610 may be manually operated ormay be connected to a controller (as described above with respect to therotation mechanism 1608) that provides control signals to activate ordeactivate the translation mechanism 1610 in response to a feedback loopthat provides a color injection probe replacement instruction due to alow quantity of liquid colorant within the color injection probe 1304.

According to various embodiments, the stream engagement portion 1516 ofthe color injection assembly 1302 that extends into the polymer streamhas features that are configured to maintain, or minimally disrupt, thelaminar flow of the polymer stream as it passes. Preventing orminimizing the disruption to the laminar flow of the polymer stream mayhelp ensure an accurate delivery of liquid colorant to the centeredposition of the polymer stream for efficient, uniform mixing through thedownstream static mixing assembly 208. FIG. 16C is a cross-sectionalview of the stream engaging portion 1516 of the color injection assembly1302 taken along the lines 16C shown in FIG. 16A. Specifically, aleading edge flow control device 1620 a may be attached to a leadingedge of the stream engaging portion 1516 of the color injection assembly1302, and a trailing edge flow control device 1620 b may be attached toa leading edge of the stream engaging portion 1516 of the colorinjection assembly 1302. Collectively, the leading edge flow controldevice 1620 a and the trailing edge flow control device 1620 b arereferred to as flow control devices 1620. The flow control devices 1620may be wedge shaped or may have any desirable airfoil cross-sectionalshape that provides for the desired flow characteristics around thestream engaging portion 1516 of the color injection assembly 1302.

As noted above, when color injection is not desired, the color injectionprobe 1304 may be removed from the color injection assembly 1302. Whilethis may initially be addressed by the pressure blocking mechanism 1524acting to fluidly decouple the color injection assembly 1302, preventingthe color injection probe 1304 from providing liquid colorant from thecolor injection probe 1304 to the polymer stream, this decoupling leavesthe color probe channel 1526 vacant, creating an opening into which thepolymer stream may flow rather than remaining in the polymer streamconduit. To prevent the resulting hindered flow of polymer stream,clogging of the color probe channel 1526 (which may require maintenanceto address), and wasted polymer, in various embodiments a color probechannel plug may be inserted into the color probe channel 1526.

As noted above, in various embodiments, the color probe channel plug mayhave substantially the same exterior shape and size as the colorinjection probe 1304 but may be solid or otherwise closed where thecolor injection probe 1304 may have an opening configured to providecolorant to the polymer stream. Alternatively, the color probe channelplug may otherwise be configured to facilitate the flow of polymer intothe color probe channel 1526. In particular embodiments, the color probechannel plug may be substantially structurally identical to the colorinjection probe 1304, except that the color probe channel plug may haveno opening corresponding to the opening of the color injection probe1304 through which colorant is designed to flow.

In particular embodiments, the color injection probe 1304 may be removedwhen the color injection assembly 1302 is in a closed configuration 1602with the color probe 1304 in a retracted position. Next, the color probechannel plug may be installed in the place of the color injection probe1304 while the color injection assembly 1302 is in a closedconfiguration 1602. Then, the color injection assembly 1302 may be putinto an open configuration 1604 with the color probe channel plug in adeployed configuration, replacing the color injection probe 1304 andfilling the color probe channel 1526, thereby facilitating improved flowof the polymer stream.

In particular embodiments, a color injection probe 1304 and/or a colorprobe channel plug may have a substantially circular cross-sectionhaving a diameter of between about one inch and about three inches(e.g., about three inches). The color probe channel 1526 may define asubstantially cylindrical interior space having a substantially circularinterior cross-section with a diameter of between about one inch andabout three inches (e.g., about three inches). Also, the color injectionprobe 1304 and/or the color probe channel plug may have a length ofbetween about one inch and about five inches (e.g., between about threeinches and about five inches) and the corresponding interior spacedefined by the color probe channel 1526 may have a corresponding lengthof between about one inch and about five inches (e.g., between aboutthree inches and about five inches).

In various embodiments, an exterior portion of the probe channel plug isdimensioned to substantially conform to an interior portion of the colorprobe channel 1526 and to thereby at least substantially create a seal(e.g., create a seal) that inhibits the flow of polymer into the colorprobe channel 1526. Per the discussion above, in particular embodiments,an exterior shape of the probe channel plug is substantially the same asa corresponding shape of the color probe.

Turning now to FIGS. 17A-17C, front, side, and top views, respectively,of a polymer injection port 1508 for providing PET 220 to a polymerstream of PTT 200 will be discussed. According to various embodiments,the polymer injection port 1508 may include a stream engaging end 1702encompassing a polymer inlet tube 1514. The stream engaging end 1702with the polymer inlet tube 1514 extends into the interior portion ofthe polymer stream to deliver PET 220 into the PTT 200. A gear pump, orother type of pump, may be operatively connected to a source of PET 220and the polymer injection port 1508 and may be activated to deliver thePET 220 into the polymer stream. The polymer injection port 1508 mayinclude cooling coils that may be used to freeze the PET 220 to stop theflow and then heat it up to re-start the flow, should it be necessary tostop the polymer flow for an equipment change or for any other reason.

FIG. 18 depicts a high level overview of a process 1800 for introducinga liquid colorant into a polymer stream during manufacturing of a bulkedcontinuous filament, according to various embodiments described herein.The process 1800 begins at operation 1802, where PTT 200 flakes, orother polymer flakes (e.g., PET 220), may be passed through an extruderthat melts the flakes and purifies the resulting polymer. At operation1804, the extruded polymer stream may then be optionally split into aplurality of polymer streams. If the polymer stream is a stream of PTT200, then PET 220 may be added downstream of the primary extruder 208 atoperation 1806. At operation 1808, a feedback loop may be used todetermine whether the color injection probe 1304 needs replacing. Ifnot, then liquid colorant may be added to each polymer stream atoperation 1810. In particular embodiments, PET may be added to PTTwithout the addition of a colorant, while in other particularembodiments, colorant may be added to PTT or PET with the addition ofanother polymer. In still other particular embodiments, PET and colorantmay be added to PTT. One or more static mixing assemblies 208 may beused to mix each of the polymer streams at operation 1812, mixing eitheror both the added colorant and/or PET 220 with molten PTT 200 accordingto the embodiment implemented. At operation 1814, each of the polymerstreams may be fed into a respective spinning machine 212 to turn thepolymer into a BCF for use in manufacturing carpets or other products.

If, at operation 1808, it is determined that the color injection probe1304 needs to be replaced or removed, then the process 1800 may proceedto operation 1816 where the transition between open and closedconfigurations 1604 and 1602, respectively, begins. At operation 1816,the color injection assembly 1302 is configured in the openconfiguration 1602, as shown in FIGS. 15 and 16B. To begin thetransition to the closed configuration 1604, the color probe 1304 isretracted from the stream engagement portion 1516 and back through thecylindrical pressure barrier 1612. After retracting the color probe 1304through the cylindrical pressure barrier 1612, at operation 1818, thecylindrical pressure barrier 1612 is rotated as described above to closeor block the color probe channel 1526 to prevent backflow of the polymerstream through the color injection assembly 1302.

At operation 1820, the color injection probe 1304 may be unscrewed orotherwise removed from the plunger 1520 and replaced with a replacementcolor injection probe. Alternatively, at operation 1820, the colorinjection probe 1304 may be unscrewed or otherwise removed from theplunger 1520 and replaced with a color probe channel plug. At operation1822, the cylindrical pressure barrier 1612 is rotated to align thecolor probe passage 1606 with the color probe channel 1526 to open thecolor injection assembly 1302 and the replacement color probe isadvanced into the polymer stream. The process 1800 may then proceed tooperation 1810 and continues as described above.

Operation 5: Using a Spinning Machine to Turn the Colored Polymer intoFilament

Referring back to FIG. 2, after the polymer stream (e.g., asubstantially PET, substantially PTT, or a mixed polymer stream) and/orthe added colorant have been sufficiently mixed using the one or morestatic mixing assemblies 208 (e.g., homogeneously mixed), the resultantcolored and/or mixed polymer stream may be fed directly into the BCF (or“spinning”) machine 212 that may be configured to turn the moltenpolymer into BCF (see, e.g., FIG. 2). In particular embodiments, thespinning machine 212 extrudes molten polymer through small holes in aspinneret in order to produce carpet yarn filament from the polymer. Inparticular embodiments, the molten recycled PET polymer cools afterleaving the spinneret. The carpet yarn may then be taken up by rollersand ultimately turned into filaments that may be used to produce carpet.In various embodiments, the carpet yarn produced by the spinning machine212 may have a tenacity between about 3 gram-force per unit denier(gf/den) and about 9 gf/den. In particular embodiments, the resultingcarpet yarn has a tenacity of at least about 3 gf/den.

In particular embodiments, the spinning machine 212 used in theprocesses described herein may be a Sytec One spinning machinemanufactured by Oerlika Neumag of Neumuenster, Germany. The Sytec Onemachine may be especially adapted for hard-to-run fibers, such as nylonor solution-dyed fibers, where the filaments are prone to breakageduring processing. In various embodiments, the Sytec One machine keepsthe runs downstream of the spinneret as straight as possible, uses onlyone threadline, and is designed to be quick to rethread when there arefilament breaks.

Although the example provided above describes using the Sytec Onespinning machine to produce carpet yarn filament from the polymer, itshould be understood that any other suitable spinning machine may beused. Such spinning machines may include, for example, any suitableone-threadline or three-threadline spinning machine, including thosemade by Oerlika Neumag of Neumuenster, Germany, or such machines made byany other company.

In various embodiments, prior to using the spinning machine 212 to spinthe colored melt into filament, the process may utilize one or morecolor sensors 210 to determine a color of the colored polymer stream. Invarious embodiments, the one or more color sensors 210 may include oneor more spectrographs configured to separate light shone through thepolymer stream into a frequency spectrum to determine the color of thepolymer stream. In still other embodiments, the one or more colorsensors 210 comprises one or more cameras or other suitable imagingdevices configured to determine a color of the resultant polymer stream.In particular embodiments, in response to determining that the color ofthe polymer stream is a color other than a desired color (e.g., thepolymer stream is lighter than desired, darker than desired, a colorother than the desired color, etc.) the system may discard the portionof the stream with the incorrect color and/or adjust an amount ofcolorant 204 that is added to the flake and/or the polymer streamupstream in order to adjust a color of the resultant polymer stream. Inparticular embodiments, adjusting the amount of colorant 204 may beperformed in a substantially automated manner (e.g., automatically)using the one or more color sensors 210 in a computer-controlledfeedback control loop.

Producing a Plurality of Different Colored Fibers Using a Single PrimaryExtruder

In addition to the single colorant added to a single polymer stream froma primary extruder 202 described above with respect to FIG. 2, theprocess described herein may be utilized to produce a plurality ofdifferent colored filament from a single primary extruder. FIG. 11depicts a process for producing a plurality of different coloredfilament from a single primary extruder (e.g., a single multiple screwextruder) according to a particular embodiment. As may be understoodfrom FIG. 11, the process involves splitting the polymer stream of PTT200 from the primary extruder 202 into a plurality of individual polymerstreams 203 a-d (e.g., four individual polymer streams) using anysuitable technique. In other embodiments, the process may includesplitting the polymer stream from the primary extruder 202 into anysuitable number of individual polymer streams (e.g., two individualpolymer streams, three individual polymer streams, four individualpolymer streams, five individual polymer streams, six individual polymerstreams, seven individual polymer streams, eight individual polymerstreams, etc.)

As shown in FIG. 11, a colorant (e.g., Colorants A-D 204 a-d) (e.g.,liquid colorant, solid colorant, molten liquid polymeric masterbatch,liquid polymeric masterbatch, solid polymeric masterbatch, compoundedcoloring material, etc.) may be added to each individual polymer stream,for example, using a respective extruder 206 a-d as described above. Forexample, Colorant C 204 c may be added to individual polymer stream 203c using extruder 206 c. In addition, or instead of adding colorant, PET220 (e.g., PET 220 a-d) may be added to each individual polymer streamat secondary extruders 206 a-d, as described above.

Once the respective Colorants A-D 204 a-d and/or PET 220 a-d has beenadded to the respective individual polymer stream 203 a-d, eachindividual polymer stream 203 a-d with added Colorant A-D 204 a-d and/orPET 220 a-d is substantially uniformly mixed using respective one ormore static mixing assemblies 208 a-d. For example, once Colorant D 204d and/or PET 220 d has been added to individual polymer stream 203 d,the resultant colorant/PET/PTT mixture passes through the one or morestatic mixing assemblies 208 d to mix the Colorant D 204 d, the PET 220d, and/or the individual polymer stream 203 d (e.g., to substantialhomogeneity). Following mixture by the one or more static mixingassemblies 208 a-d, the resultant respective colored polymer streams maybe spun into filament using respective spinning machines 212 a-d.

In various embodiments, it may be important to monitor the output of theextruder to determine a throughput of each individual polymer stream 203a-d. In such embodiments, monitoring throughput may ensure that eachindividual polymer stream 203 a-d has the proper color letdown ratio inorder to add a proper amount of Colorants A-D 204 a-d to achieve adesired color of BCF.

As may be understood from FIG. 11, splitting extruded polymer from aprimary extruder 202 into a plurality of polymer streams 203 a-d priorto the addition of colorant may enable the production of a plurality ofcolored filament using a single primary extruder 202. Furthermore, byusing a plurality of different colorants and extruders downstream of theprimary extruder 202, the process may facilitate a reduction in wastewhen changing a colorant used. For example, when using a single extruderin which color is added upstream of the extruder, there is wasteassociated with changing over a color package in that the extruder mustrun for a sufficiently long amount of time between changes to ensurethat all of the previous color has cleared the extruder (e.g., such thatnone of the previous color will remain and mix with the new color). Insome cases, the wasted filament as a result of a switch in color mayinclude up to several thousand pounds of filament (e.g., up to 4000pounds). Using a (e.g., smaller) secondary extruder 206 a-d to introducecolorant to the various individual polymer streams 203 a-d downstreamfrom the primary extruder 202 may reduce (e.g., substantially reduce)the amount of waste associated with a changeover of colorant (e.g., tobelow about 100 pounds per changeover). Moreover, adding PET 220 at thesecondary extruders, at the static mixing assemblies, and/or within thestatic mixing assemblies significantly shortens the holdup time, whichmay improve the characteristics of the mixed polymer stream prior tospinning the polymer mixture into BCF.

ALTERNATIVE EMBODIMENTS

Various embodiments of a process for producing various colored bulkedcontinuous filament may include features that vary from or are inaddition to those described above. Exemplary alternative embodiments aredescribed below.

Addition of Liquid Colorant to Polymer Stream Using Pump

FIG. 12 depicts an alternative process flow that in many respects may besimilar to the process flow shown in FIG. 11. In the particularembodiments illustrated by FIG. 12, however, liquid colorant 204 a-d isadded to the individual polymer streams 203 a-d using a pump 214 a-drather than an extruder. In such embodiments, using a liquid colorantmay have the benefit of additional cost saving due to not having to useadditional secondary extruders (e.g., which may have a greater initialcost outlay than a pump, greater running costs than a pump, etc.). Inparticular embodiments in which a pump 214 a-d is used to inject theliquid colorant 214 a-d into the individual polymer streams 203 a-d, theprocess may further include exchanging a hose used to connect the pump214 a-d to the individual polymer streams 203 a-d when exchanging aparticular liquid colorant (e.g., liquid colorant 204 a) for a differentliquid colorant (e.g., a liquid colorant of a different color). Byexchanging the hose when exchanging colorants, waste may further bereduced in that the replacement hose is pre-purged of any residualcolorant of the previous color. The color injection assemblies or ports1302 described above with respect to FIGS. 15 and 16A-16C may beutilized in the embodiments described in regard to FIG. 12 and in theembodiments associated with FIG. 11. Moreover, this example also showsthe addition of PET 220 a-d using pumps 224 a-d. The polymer injectionports 1508 described above with respect to FIGS. 15 and 17A-17C may beutilized to inject PET 220 a-d in this example. In various embodiments,any combination of pump and extruders may be used (e.g., pumps forcolorant and extruder for PET, extruder for PET and pump colorant).

CONCLUSION

Many modifications and other embodiments of the disclosure will come tomind to one skilled in the art to which this disclosure pertains havingthe benefit of the teachings presented in the foregoing descriptions andthe associated drawings. In addition, it should be understood thatvarious embodiments may omit any of the steps described above or addadditional steps. Furthermore, any numerical ranges described herein areintended to capture every integer and fractional value within thedescribed range (e.g., every rational number value within the describedrange).

For example, it should be understood that a range describing a letdownration of between about two percent and about eight percent is intendedto capture and disclose every rational number value percentage betweentwo percent and eight percent (e.g., 2%, 3%, 4%, 5%, 6%, 7%, 8%, 2.1%,2.01%, 2.001% . . . 7.999% and so on). Additionally, terms such as“about,” “substantially,” etc., when used to modify structuraldescriptions or numerical values, are intended to capture the statedshape, value, etc. as well as account for slight variations as a resultof, for example, manufacturing tolerances. For example, the term“substantially rectangular” is intended to describe shapes that are bothexactly rectangular (e.g., have four sides that meet at ninety degreeangles) as well as shapes that are not quite exactly rectangular (e.g.,shapes having four sides that meet at an angle in an acceptabletolerance of ninety degrees, such as 90°+/−4°)

In light of the above, it is to be understood that the disclosure is notto be limited to the specific embodiments disclosed and thatmodifications and other embodiments are intended to be included withinthe scope of the appended claims. Although specific terms are employedherein, they are used in a generic and descriptive sense only and notfor the purposes of limitation.

What is claimed is:
 1. A method of manufacturing bulked continuouscarpet filament from polytrimethylene terephthalate (PTT), the methodcomprising: providing an extruder; using the extruder to at leastpartially melt the PTT into a polymer stream and at least partiallypurify the polymer stream; providing a static mixing assembly downstreamof the extruder; adding polyethylene terephthalate (PET) to the polymerstream downstream of the extruder and before the static mixing assemblyor along a length of the static mixing assembly between an upstream endand a downstream end of the static mixing assembly; using the staticmixing assembly to mix the polymer stream with the PET to create a mixedpolymer stream; forming the mixed polymer stream into bulked continuouscarpet filament; splitting the polymer stream into a plurality ofindividual polymer streams downstream from the extruder; and providing,for each stream of the plurality of individual polymer streams, arespective secondary extruder and a respective static mixing assembly,wherein adding the PET, using the static mixing assembly, and formingthe mixed polymer stream into bulked continuous carpet filament occurswith respect to each stream of the plurality of individual polymerstreams.
 2. The method of claim 1, further comprising adding a liquidcolorant to the polymer stream before the static mixing assembly oralong the length of the static mixing assembly between the upstream endand the downstream end of the static mixing assembly, wherein using thestatic mixing assembly to mix the polymer stream with the PET to createthe mixed polymer stream comprises using the static mixing assembly tomix the polymer stream with the PET and the liquid colorant to create acolored mixed polymer stream, and wherein forming the mixed polymerstream into the bulked continuous carpet filament comprises forming thecolored mixed polymer stream into the bulked continuous carpet filament.3. The method of claim 1, further comprising adding a molten polymericmasterbatch to the polymer stream before the static mixing assembly oralong the length of the static mixing assembly between the upstream endand the downstream end of the static mixing assembly, wherein using thestatic mixing assembly to mix the polymer stream with the PET to createthe mixed polymer stream comprises using the static mixing assembly tomix the polymer stream with the PET and the molten polymeric masterbatchto create a colored mixed polymer stream, and wherein forming the mixedpolymer stream into the bulked continuous carpet filament comprisesforming the colored mixed polymer stream into the bulked continuouscarpet filament.
 4. The method of claim 1, further comprising adding aliquid colorant to each stream of the plurality of individual polymerstreams before the respective static mixing assembly or along the lengthof the respective static mixing assembly between the upstream end andthe downstream end of the static mixing assembly, wherein using thestatic mixing assembly to mix the polymer stream with the PET to createthe mixed polymer stream comprises using the respective static mixingassembly to mix each stream of the plurality of individual polymerstreams with the PET and the liquid colorant to create a respectivecolored mixed polymer stream, and wherein forming the mixed polymerstream into the bulked continuous carpet filament comprises forming therespective colored mixed polymer stream into the bulked continuouscarpet filament.
 5. The method of claim 1, further comprising adding amolten polymeric masterbatch to each stream of the plurality ofindividual polymer streams, wherein using the static mixing assembly tomix the polymer stream with the PET to create the mixed polymer streamcomprises using the respective static mixing assembly to mix each streamof the plurality of individual polymer streams with the PET and themolten polymeric masterbatch to create a respective colored mixedpolymer stream, and wherein forming the mixed polymer stream into thebulked continuous carpet filament comprises forming the respectivecolored mixed polymer stream into the bulked continuous carpet filament.6. The method of claim 5, wherein adding the molten polymericmasterbatch to each stream of the plurality of individual polymerstreams comprises adding the molten polymeric masterbatch to therespective secondary extruder.
 7. The method of claim 5, wherein addingthe molten polymeric masterbatch to each stream of the plurality ofindividual polymer streams comprises adding the molten polymericmasterbatch before the respective static mixing assembly or along thelength of the respective static mixing assembly between the upstream endand the downstream end of the respective static mixing assembly.
 8. Amethod of manufacturing bulked continuous carpet filament frompolytrimethylene terephthalate (PTT), the method comprising: providingan extruder; using the extruder to at least partially melt the PTT intoa polymer stream and at least partially purify the polymer stream;providing a static mixing assembly downstream of the extruder; adding aliquid colorant to the polymer stream before the static mixing assemblyor along a length of the static mixing assembly between an upstream endand a downstream end of the static mixing assembly; using the staticmixing assembly to mix the polymer stream with the liquid colorant tocreate a colored polymer stream; forming the colored polymer stream intobulked continuous carpet filament; splitting the polymer stream into aplurality of individual polymer streams downstream from the extruder;and providing, for each stream of the plurality of individual polymerstreams, a respective secondary extruder and a respective static mixingassembly, wherein adding the liquid colorant, using the static mixingassembly, and forming the colored polymer stream into the bulkedcontinuous carpet filament occurs with respect to each stream of theplurality of individual polymer streams.
 9. The method of claim 8,further comprising adding polyethylene terephthalate (PET) to thepolymer stream; wherein using the static mixing assembly to mix thepolymer stream with the liquid colorant to create the colored polymerstream comprises using the static mixing assembly to mix the polymerstream with the liquid colorant and the PET to create a colored mixedpolymer stream, and wherein forming the colored polymer stream into thebulked continuous carpet filament comprises forming the colored mixedpolymer stream into the bulked continuous carpet filament.
 10. Themethod of claim 9, wherein adding the PET to the polymer streamcomprises adding the PET to the extruder.
 11. The method of claim 9,wherein adding the PET to the polymer stream comprises adding the PETbefore the static mixing assembly or along the length of the staticmixing assembly between the upstream end and the downstream end of thestatic mixing assembly.
 12. The method of claim 8, further comprisingadding polyethylene terephthalate (PET) to each stream of the pluralityof individual polymer streams, wherein using the static mixing assemblyto mix the polymer stream with the liquid colorant to create the coloredpolymer stream comprises using the respective static mixing assembly tomix each stream of the plurality of individual polymer streams with theliquid colorant and the PET to create a respective colored mixed polymerstream, and wherein forming the colored polymer stream into the bulkedcontinuous carpet filament comprises forming the respective coloredmixed polymer stream into the bulked continuous carpet filament.
 13. Themethod of claim 12, wherein adding the PET to each stream of theplurality of individual polymer streams comprises adding the PET beforethe respective static mixing assembly or along the length of therespective static mixing assembly between the upstream end and thedownstream end of the respective static mixing assembly.
 14. A method ofmanufacturing bulked continuous carpet filament from polytrimethyleneterephthalate (PTT), the method comprising: providing an extruder; usingthe extruder to at least partially melt the PTT into a polymer streamand at least partially purify the polymer stream; providing a staticmixing assembly downstream of the extruder; adding a molten polymericmasterbatch to the polymer stream before the static mixing assembly oralong a length of the static mixing assembly between an upstream end anda downstream end of the static mixing assembly; using the static mixingassembly to mix the polymer stream with the molten polymeric masterbatchto create a colored polymer stream; forming the colored polymer streaminto bulked continuous carpet filament; splitting the polymer streaminto a plurality of individual polymer streams downstream from theextruder; and providing, for each stream of the plurality of individualpolymer streams, a respective secondary extruder and a respective staticmixing assembly, wherein adding the molten polymeric masterbatch, usingthe static mixing assembly, and forming the colored polymer stream intothe bulked continuous carpet filament occurs with respect to each streamof the plurality of individual polymer streams.
 15. The method of claim14, further comprising adding polyethylene terephthalate (PET) to thepolymer stream, wherein using the static mixing assembly to mix thepolymer stream with the molten polymeric masterbatch to create thecolored polymer stream comprises using the static mixing assembly to mixthe polymer stream with the molten polymeric masterbatch and the PET tocreate a colored mixed polymer stream, and wherein forming the coloredpolymer stream into the bulked continuous carpet filament comprisesforming the colored mixed polymer stream into the bulked continuouscarpet filament.
 16. The method of claim 14, further comprising addingpolyethylene terephthalate (PET) to each stream of the plurality ofindividual polymer streams, wherein using the static mixing assembly tomix the polymer stream with the molten polymeric masterbatch to createthe colored polymer stream comprises using the respective static mixingassembly to mix each stream of the plurality of individual polymerstreams with the molten polymeric masterbatch and the PET to create arespective colored mixed polymer stream, and wherein forming the coloredpolymer stream into the bulked continuous carpet filament comprisesforming the respective colored mixed polymer stream into the bulkedcontinuous carpet filament.
 17. The method of claim 16, wherein addingthe PET to each stream of the plurality of individual polymer streamscomprises adding the PET to the respective secondary extruder.